Increased oxidation of extracellular glutathione by bronchoalveolar inflammatory cells in diffuse fibrosing alveolitis

An unbalanced oxidative stress is thought to be an important element in the pathogenesis of diffuse fibrosing alveolitis (DFA). The purpose of our study was to investigate the role of reactive oxygen metabolites (ROMs) released from cultured bronchoalveolar inflammatory cells (BA-cells) on glutathione oxidation. We studied bronchoalveolar lavage samples from 10 healthy controls and from 20 patients with diffuse fibrosing alveolitis (all were nonsmokers). BA-cells obtained by bronchoalveolar lavage (BAL) were incubated with 50 microM of reduced glutathione (GSH). Oxidation of GSH to glutathione disulphide (GSSG) by BA-cell derived oxidants was detected as a decline of GSH in the supernatants. Total glutathione (GSHtot = GSH + 2 GSSG) and GSSG in the epithelial lining fluid (ELF), and methionine sulphoxide (Met(O)) content of BAL proteins were determined. In diffuse fibrosing alveolitis the oxidative activity of BA-cells was enhanced, GSHtot and GSH were decreased, whereas the GSSG:GSH ratio was increased. The oxidative activity of BA-cells correlated positively with the GSSG:GSH ratio, but not with the methionine sulphoxide content. The methionine sulphoxide content was elevated in diffuse fibrosing alveolitis and inversely correlated with GSHtot. The methionine sulphoxide content also correlated positively with the percentage of BAL neutrophils. We conclude that BA-cell-derived reactive oxygen species are capable of oxidizing extracellular GSH in vitro. The positive correlation between the BA-cell oxidative activity in vitro and GSSG:GSH ratio in ELF suggests that a similar oxidative effect on extracellular GSH may also occur in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pulmonary manifestations of systemic scleroderma: pathophysiologic and clinical significance of the activation of lung fibroblasts]

Fibrosing alveolitis (FA) is a common and often fatal complication of systemic sclerosis (SSC). The purpose of this study was to characterize the fibrotic process within the lungs using bronchoalveolar lavage fluid (BALF). We investigated 25 healthy controls (CON) and 85 SSC patients. In 61 patients (72%) lung function tests, clinical, and radiological findings indicated manifest FA, whereas 24 patients (28%) where free of significant lung disease. Of the latter, 12 had pathologic BAL differential cell counts (= subclinical alveolitis; SUB), 12 had normal BAL cytology (NOR). BAL samples were analysed for chemoattractant activity (CAA) for fibroblasts using Boyden chambers. Procollagen-III-Peptide (P-III-P) and Laminin fragment P1 (Lam-P1) were measured radioimmunologically. CAA (expressed as % of the effect of conditioned medium) was increased in FA and SUB (CON: 17.3 +/- 3.2; FA: 40.8 +/- 5.8, p < 0.01 vs. CON; SUB: 58.6 +/- 11.8, p < 0.01 vs. CON; NOR: 23.7 +/- 6.3; n.s.). Lam-P1 [U/ml ELF] was also elevated in FA and SUB patients (CON: 0.90 +/- 0.17; FA: 2.07 +/- 0.48, p < 0.05 vs. CON; SUB: 2.61 +/- 1.14, p < 0.05 vs. CON; NOR: 1.05 +/- 0.35, n.s. vs. CON). P-III-P [U/ml ELF] was elevated in FA patients (CON: 8.3 +/- 1.1; FA: 26.9 +/- 5.5, p < 0.001 vs. CON) but not in SUB or NOR (SUB: 10.2 +/- 0.7, NOR: 7.9 +/- 2.9; n.s.). There was no significant relationship between P-III-P and LAM-P1 values in ELF and serum, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of white blood cell staining by intravascular administration of rhodamine 6G

Rhodamine 6G is a vital dye accumulating in the mitochondria of cells. It is used in intravital fluorescence microscopy for contrast enhancement of white blood cells (WBC), enabling visualization of WBC in the microvasculature even at high center flow velocity. The aim of this study was to examine the kinetics of WBC staining after intravascular administration of rhodamine 6G in Lewis rats, Syrian golden hamsters and BALB/c mice. For this purpose, WBC were isolated from whole blood and the percentage of cells stained positively as well as their fluorescence intensity were measured by flow cytometry 5, 15, 30 and 60 min after dye administration. Injection of 0.06-0.2 mg/kg body weight of rhodamine 6G resulted in staining practically all granulocytes and monocytes over the entire observation period of 60 min. Fluorescence intensity of WBC was adequate to be detected in an experimental setup for intravital fluorescence microscopy in the hamster dorsal skinfold chamber. The degree of WBC staining was different in the species studied, yielding a higher percentage of stained lymphocytes in rats than in mice and hamsters. Staining of lymphocytes declined within 60 min after rhodamine application, the loss of fluorescent label being most pronounced in hamster cells. After 15-30 min, relative fluorescence intensity of stained lymphocytes had decreased considerably, indicating the need for reinjection of the dye or limiting microscopic analysis to approximately 15 min after rhodamine 6G administration. While the intravascular injection of rhodamine 6G results in adequate staining of granulocytes and monocytes, only a fraction of lymphoid cells are stained.

In vitro effects of oxidized low density lipoprotein on CD11b/CD18 and L-selectin presentation on neutrophils and monocytes with relevance for the in vivo situation

Oxidized LDL (oxLDL) has been identified as a potent stimulus of leukocyte adhesion to endothelium, a hallmark of early atherogenesis. A cytofluorometric study was performed to further characterize the mechanisms by which oxLDL stimulates the rapid adhesion of leukocytes to endothelium in vitro and in vivo. Incubation (30 minutes at 37 C) of whole blood (diluted with buffered saline to 1 x 10(6) leukocytes/ml) with oxLDL (0.85 mg LDL cholesterol/ml; oxidized by 7.5 mumol/L Cu2+ for 18 hours) but not native LDL stimulated the upregulation of CD11b/CD18 adhesion receptors on neutrophils (anti-leu-15 binding: 178 +/- 16% of baseline, P < 0.01, means +/- SD of n = 10 experiments) and on monocytes (169 +/- 34% of baseline, P < 0.01). This phenomenon was almost entirely inhibited by n-butanol or the vasoactive drug pentoxifylline (PTX), which also significantly reduced oxLDL-induced leukocyte adhesion to venular and arteriolar endothelium, as assessed by intravital microscopy on the dorsal skinfold chamber in hamsters (venules: 49 +/- 19 versus 120 +/- 34 cells/mm2, P < 0.05; arterioles: 9 +/- 4 versus 52 +/- 7 cells/mm2, P < 0.01) 30 minutes after intravenous injection of oxLDL (4 mg/kg body weight; means +/- SD of n = 7 hamsters per group). Butanol and PTX also significantly reduced the upregulation of CD11b/CD18 by f-methionyl-leucyl-phenylalanine (fMLP) and platelet-activating factor (PAF) but not by phorbol myristate acetate (PMA). Whereas fMLP and PAF stimulate leukocytes via binding to specific cell surface receptors and triggering complex signal transduction pathways, PMA bypasses these pathways and directly activates intracellular protein kinase C. By analogy, we propose that oxLDL upregulates CD11b/CD18 through its previously documented ability to stimulate the generation of second messengers. The effect of n-butanol and PTX on receptor presentation cannot be explained by changes in plasma membrane fluidity, as both agents failed to reverse the decrease in plasma membrane fluidity of neutrophils after stimulation with oxLDL, as assessed by fluorescence anisotropy measurement of the membrane marker diphenylhexatriene. Incubation of isolated neutrophils but not of whole blood with oxLDL resulted in a significant loss of L-selectin from the neutrophil surface (anti-TQ-1 binding: 40 +/- 13% of baseline, P < 0.01). A significant loss of this adhesion receptor on neutrophils and monocytes was also observed after stimulation of isolated neutrophils and whole blood with fMLP, PAF, and PMA.(ABSTRACT TRUNCATED AT 400 WORDS)

Pathogenetic and clinical significance of fibroblast activation in scleroderma lung disease

Fibrosing alveolitis (FA) is a major and often fatal complication of systemic sclerosis (SSC). The critical role of fibroblasts in the pathogenesis of FA has long been recognized. Characterization of fibroblast activation in the lungs may improve our understanding and the management of this disease. We analyzed bronchoalveolar lavage (BAL) fluid samples from 9 healthy controls and 43 patients with FA caused by lung involvement form SSC. The chemoattractant activity (CAA) of cultured human fibroblasts elicited by native BAL fluid was measured in Boyden chambers. In addition, procollagen III peptide was measured in BAL fluid as a marker of collagen synthesis. CAA (expressed as percentage of the chemoattractant effect of 0.25 ng/ml platelet-derived growth factor; PDGF) was elevated in the SSC patients compared with that of the controls (control: 12.6 +/- 4.0%; SSC: 68.8 +/- 15.2%; p < 0.01). A positive correlation was found between BAL total cell count and CAA (r = 0.60, p < 0.01). An inverse correlation existed between CAA and total lung capacity (r = -0.55, p < 0.05). The patients were followed up for 13.3 +/- 1.4 months (mean +/- SEM). Twenty-seven patients received immunosuppressive therapy, whereas 16 refused therapy. The patients were assigned to two groups according to their CAA being lower or higher than 36% of the PDGF response (= mean value of the controls + 2 SD).

Short-term and long-term effects of serial bronchoalveolar lavages in a nonhuman primate model

Bronchoalveolar lavage (BAL) has gained widespread use as a tool for investigating human lung diseases. In certain cases, it can be useful to obtain BAL material in a serial manner. There is convincing evidence from experimental and clinical studies that BAL can cause influx of neutrophils into the bronchoalveolar space. However, conflicting data have been reported on whether this side effect of BAL also affects previously nonlavaged lung areas. In addition, there is little information available on whether multiple repetitive BAL procedures cause damage to lung tissue. To reexamine the short-term effects of serial BAL procedures, the left lung of 10 cynomolgus monkeys was lavaged with five 20-ml aliquots of saline four times at 24-h intervals (Group A). 72 h after the initial BAL, the right lung was lavaged as a control. The percentage of neutrophils increased significantly (p < 0.05), with the greatest effect seen at 48 h (30.7 +/- 5.8 versus 0.8 +/- 0.3%, mean +/- SEM). No significant changes were observed in the control BAL of the right lung at 72 h. A multidisciplinary approach was used to assess the long-term effects of multiple BAL procedures. BAL was performed 14 times over 26 mo at 2-mo intervals (Group B, n = 5). The right lung was lavaged as a control 25 mo after the initial BAL. In addition to standard cellular BAL parameters, the concentrations of fibronectin, procollagen III amino-terminal peptide-related antigen, total phospholipids, and lactate dehydrogenase activity were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of blood neutrophils in acute episodes of farmer's lung

Farmer's lung often presents clinically as recurring acute episodes several hours after exposure to moldy hay. During these episodes the blood neutrophil count increases. Because activated neutrophils release toxic oxygen metabolites and proteinases, we hypothesized that the pulmonary reaction in farmer's lung may be induced by the secretory products of activated neutrophils. To evaluate this concept, we quantified the respiratory burst of separated blood neutrophils from patients with farmer's lung (n = 12) during standardized exposure tests with moldy hay. The respiratory burst of these cells was evaluated by measuring zymosan-stimulated and lucigenin-amplified chemiluminescence (CL). Asymptomatic farmers (n = 12) and normal volunteers with no prior exposure to moldy hay (n = 15) were used as control subjects. As expected, following exposure in the group of patients with farmer's lung, striking changes in VC, TLCO, and PaO2 were observed, whereas there were only minor changes in these parameters in both control groups. In all three groups a considerable increase in the blood leukocyte count was observed. The CL response of the blood neutrophils from patients with farmer's lung 6 h after exposure was significantly higher than before or 1 h after exposure (p < 0.05 for both comparisons), whereas there was no significant change in the CL response in either control group during the observation period. Our results indicate that antigen inhalation induces an increase in the number of circulating neutrophils in patients and controls, but in patients with an acute episode of farmer's lung the neutrophils are primed for an enhanced respiratory burst and may thereby damage the lung.

Mechanisms of cytokine cascade activation in patients with sepsis: normal cytokine transcription despite reduced CD14 receptor expression

BACKGROUND

Lipopolysaccharide causes activation of monocytes/macrophages with excessive secretion of cytokines resulting in hypotension and shock in patients with sepsis. Lipopolysaccharide may induce these responses by interacting with lipopolysaccharide-binding protein and then binding to the cell surface protein CD14 or by acting directly with CD11-CD18 on monocytes/macrophages. The role of CD14 and CD11-CD18 in the activation of macrophages with enhanced cytokine transcription in patients with septic shock remains to be determined.

METHODS

To study this, heparinized blood was obtained from 16 patients with septic shock on days 0, 1, 3, 5, 7, and 10 and compared with 20 control patients. The expression of CD14 and CD11b on monocytes in whole blood was measured by direct immunofluorescence and flow cytometry. Moreover, whole blood was stimulated with lipopolysaccharide (1 microgram/ml) for 0, 1, 2, 4, 8, and 24 hours, and messenger RNA expression for tumor necrosis factor-alpha, interleukin-beta (IL-1 beta), and IL-6 was determined on isolated peripheral blood mononuclear cells with Northern blot analysis.

RESULTS

Both CD14 expression and receptor density on monocytes from whole blood were markedly suppressed (-63% on day 3; p < 0.05) in the septic group compared with controls. Although CD11b expression was also decreased (-24% on day 1; p < 0.05), receptor density on monocytes was slightly increased in the septic group in comparison with the control group. Kinetics and intensity of messenger RNA expression for tumor necrosis factor-alpha, IL-1 beta, and IL-6 were similar in both groups.

CONCLUSIONS

These data indicate that in patients with septic shock, lipopolysaccharide-mediated signaling and cytokine transcription are unchanged despite a significant reduction of CD14 expression and density on monocytes. Thus, lipopolysaccharide-induced activation of monocytes from patients with sepsis may occur through direct binding of lipopolysaccharide to the CD11-CD18 complex or other lipopolysaccharide receptors, whereas binding of the lipopolysaccharide-lipopolysaccharide-binding protein complex to the CD14 receptor may not play a pivotal role in sepsis.

Fibroblast chemotactic response elicited by native bronchoalveolar lavage fluid from patients with fibrosing alveolitis

BACKGROUND

In fibrosing alveolitis activation of lung fibroblasts is the decisive event in the pathogenetic sequence leading to pulmonary fibrosis. Fibroblast stimulating activity was measured in bronchoalveolar lavage (BAL) fluid to assess its relationship to the activity of fibrosing alveolitis.

METHODS

Nine control subjects and 40 patients with fibrosing alveolitis caused by idiopathic pulmonary fibrosis (n = 22) or pulmonary involvement in systemic sclerosis (n = 18) were studied. All patients were followed up by lung function testing for a minimum of six months (mean (SE) 13.3 (1.4) months). Twenty five patients received immunosuppressive therapy and 15 refused. At the beginning of follow up BAL was performed and, as a possible indicator of fibroblast stimulating mediators within the lungs, chemotactic migration of cultured human fibroblasts elicited by native BAL fluid was measured in Boyden-type chambers and expressed as a percentage of the chemoattractant effect of 25 ng/ml platelet derived growth factor. The procollagen III peptide level in BAL fluid served as a marker for collagen synthesis.

RESULTS

Chemoattractant activity was elevated in the patients with idiopathic pulmonary fibrosis and systemic sclerosis compared with the control group, (mean (SE) 56.4% (8.5%)) and 72.3% (16.3%) v 12.6% (4.0%). Chemoattractant activity was inversely correlated with total lung capacity (TLC) (r = -0.45) and with vital capacity (VC) (r = -0.33). Procollagen III peptide concentrations in BAL fluid and chemoattractant activity were not significantly correlated. For further evaluation chemoattractant activity of 36% (mean value of controls +2 SD) was used to separate normal (< 36%) from elevated (> or = 36%) activity. At the end of follow up, untreated patients with high chemoattractant activity (> or = 36%) showed a significant reduction of VC, TLC, and exercise arterial oxygen tension (PaO2) and a small decrease in carbon monoxide transfer factor (TLCO), whereas a significant improvement in VC, TLC, and TLCO and a small increase of exercise PaO2 occurred in treated patients with high chemoattractant activity. Patients with low chemoattractant activity (< 36%) showed no consistent change in lung function measurements, irrespective of treatment. In contrast, lung function results and differential cell counts in BAL fluid failed to identify progressive disease.

CONCLUSIONS

In patients with fibrosing alveolitis the chemoattractant activity of BAL fluid seems to be an independent indicator of lung fibroblast stimulating activity providing relevant information about disease activity, and may help to improve the clinical management of these patients.

Attenuation of postischemic microvascular disturbances in striated muscle by hyperosmolar saline dextran

The underlying mechanisms of the beneficial therapeutic effects of small-volume resuscitation with hyperosmolar solutions for treatment of hypovolemic shock are still poorly understood. Using the dorsal skinfold chamber model and intravital fluorescence microscopy, we investigated the effects of hyperosmolar saline dextran on ischemia-reperfusion injury in striated skin muscle of awake normovolemic golden hamsters. Test solutions (4 ml/kg body wt i.v.) were administered 2 min before reperfusion after 4 h of pressure-induced ischemia. In animals receiving 0.9% saline (control), we observed a drastic enhancement of leukocyte rolling along and sticking to the endothelium of postcapillary venules 0.5 h after reperfusion. Postischemic leukocyte rolling and sticking were significantly reduced when animals were treated with 7.2% saline alone (HSS), 10% Dextran 60 in 0.9% saline (HDS), or 10% Dextran 60 in 7.2% saline (HHS). In control animals, capillary perfusion was reduced to approximately 60% of preischemic values 0.5 h after reperfusion. Concomitantly, leakage of the macromolecule fluorescein isothiocyanate-dextran (5 mg in 0.1 ml saline i.v., M(r) 150,000) into the perivascular space increased from 0% before ischemia to approximately 12% at 0.5 h reperfusion. In contrast, when animals were treated with HSS, HDS, or HHS before reperfusion, capillary perfusion decreased to a significantly minor extent of approximately 15%, and macromolecular leakage was slightly increased to approximately 5%. Our results suggest that hyperosmolar saline dextran effectively attenuates postischemic microvascular disturbances elicited by ischemia-reperfusion, presumably through reduction of postischemic leukocyte-endothelium interaction and capillary swelling.

Heterogeneity of alveolar macrophages in experimental silicosis

The alveolar macrophage (AM) population has been shown to be heterogeneous in composition as well as in function. The aim of our study was to assess morphological and functional features of AM in an experimental model of quartz-induced lung fibrosis by flow cytometric methods. Twelve cynomolgus monkeys were exposed 8 hr/day, 5 days/week for 26 months to either normal atmosphere (n = 5) or 5 mg/m3 DQ12 less than 5 microns quartz dust (n = 7). After 20 months of exposure, we studied AM phagocytosis by incubating bronchoalveolar lavage cells with fluorescent polystyrene microspheres (mean diameter 1.91 microns). Using a fluorescence-activated cell sorter analyzer, AM subpopulations were identified via their volume/side scatter properties. After selective electronic "gating" of the AM populations, both the percentage of phagocytic AM and the mean number of ingested microspheres per AM were determined. In addition, a phagocytic index (microspheres/AM x % phagocytic AM x 10(-2) and a hypothetical total phagocytic capacity of one lung (phagocytic index x total number of AM x 10(-6) were calculated. The total bronchoalveolar lavage cell counts rose (75.6 +/- 11.3 x 10(6) versus 10.1 +/- 0.8 x 10(6)) significantly after quartz exposure. In contrast, the percentage of phagocytic AM was significantly (p less than 0.05) reduced (43.5 +/- 5.0% versus 74.2 +/- 1.4%). Flow cytometric measurements revealed the appearance of an AM subpopulation characterized by size/granularity features identical to blood monocytes. Only minimal numbers of these cells were found under normal conditions, but they constituted 50% of the entire AM population in the quartz group.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxidative stress in vivo and in vitro: modulation by quartz dust and hyperbaric atmosphere

Changes in the oxidative status in the soluble proteins of bronchoalveolar lavage (BAL) fluid from monkeys were examined during 26 months of individual or combined exposure to quartz dust (5 mg/m3 of DQ12) and a hyperbaric atmosphere (2.5 bar). The oxidation of BAL proteins, assumed to be an indicator for oxidative stress in the lungs, was determined by measuring the amount of carbonyl groups in their amino acid side chains. The carbonyl content of BAL proteins (nmol carbonyl/mg protein) increased steadily to a maximum value of 156% of the control after 6 months exposure to hyperbaric atmosphere, and decreased below 50% of control levels in both the quartz alone exposed group and the group exposed to quartz in combination with a hyperbaric atmosphere. The effect of quartz on the production of reactive oxygen species by BAL cells was investigated in vitro. BAL cells from healthy monkeys preincubated with quartz and stimulated with phorbol-myristate acetate (PMA) produced reduced levels of extracellular superoxide anion and intracellular hydrogen peroxide compared with PMA-only stimulated cells. Thus the lowered carbonyl content of BAL proteins in the quartz exposed groups may have resulted from reduced production of the hydrogen peroxide which is essential for carbonyl formation by phagocytes. Changes in carbonyl content of BAL protein in vivo may be a new indicator for potential subsequent lung damage.

Imaging of leukocytes within the rat brain cortex in vivo

Confocal laser scanning microscopy was used in a rat closed cranial window preparation in order to study rhodamin 6G-labeled leukocytes within the brain cortex in vivo. Leukocytes were visualized up to 150 microns beneath the rat brain surface in noninvasive optical sections. In pial venules, leukocytes were seen flowing with the blood stream, rolling along or sticking to the endothelium, and migrating through the vessel wall. Within cerebral capillaries, leukocyte flux, velocities, and leukocyte plugging were measured. After additional intravenous administration of fluorescein, the plasma, leukocytes, and erythrocytes were visualized simultaneously. Based on stacks of optical sections of fluorescein-labeled capillaries, the individual capillaries were localized within the three-dimensional microvascular network. The usefulness of this technique was illustrated in a feasibility study in which leukocyte sticking to the vascular walls of venules, leukocyte extravasation, and intracapillary leukocyte plugging were monitored in a model of global cerebral ischemia.

Pathogenetic significance of reactive oxygen species in diffuse fibrosing alveolitis

Excessive release of reactive oxygen metabolites (ROM) from lung inflammatory cells has been claimed to be of major pathogenetic significance in diffuse fibrosing alveolitis. In the present study, the content of oxidized methionine residues [Met(O)] as a percentage of total methionine (Met) in BAL-derived proteins was used to assess the biologic effect of ROM. In addition, procollagen-III-peptide was measured in BAL fluid as a marker of fibroblast activation. We investigated bronchoalveolar lavage (BAL) samples from seven control patients without evidence of interstitial lung disease and from 42 patients with fibrosing alveolitis caused by idiopathic pulmonary fibrosis (IPF), n = 20, or by collagen vascular disease (CVD), n = 22. Met(O) was elevated in the patients with IPF or CVD compared with that in the control subjects (8.86 +/- 1.26 and 8.13 +/- 1.44% versus 3.36 +/- 0.49%, p less than 0.01 and p less than 0.05, respectively; mean +/- SEM). A positive correlation was found between percentage of neutrophils in BAL and Met(O) in both groups separately and combined (IPF, r = 0.84; p less than 0.001; CVD, r = 0.44; p less than 0.05; IPF and CVD, r = 0.60; p less than 0.001), whereas an inverse relationship existed between Met(O) and the percentage of alveolar macrophages in BAL (IPF, r = -0.59; p less than 0.01; CVD, r = -0.24; NS; IPF and CVD, r = -0.41; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of class II antigens on human nasal cartilage

The presence and distribution of class II antigens on human nasal cartilage was investigated using monoclonal antibodies directed against HLA-DR, HLA-DP, and HLA-DQ molecules. Tissue sections and chondrocytes in suspension were prepared for immunoperoxidase staining and flow cytometric analysis. Class II antigens were detected primarily on the perichondrium. In contrast, chondrocytes, either isolated or in tissue sections, were completely negative, suggesting that cells of the perichondrium, may, by themselves, be capable of initiating a rejection process.

Proliferation rates of lymphocytes in subcutaneously transposed spleen and peripheral blood after heterotopic heart transplantation in rats

In a transplantation model using Dark Agouti rats as heart donors and Lewis rats as recipients, mean graft survival time was 7.1 days in GII, receiving no immunosuppression, and 31.4 days in GIII, animals immunosuppressed by DSG. A higher percentage of Lb in the spleen than in the PB in the transplanted groups was detected on certain days. HCT sharply decreased in immunosuppressed animals, thus suggesting a reversible suppression of erythropoesis induced by DSG.

The effect of gamma-interferon on HLA class II antigen expression on isolated human nasal chondrocytes

HLA class II antigens play an important role in the immunological response. In this study, we report on HLA class II antigen expression in vitro by human nasal cartilage cells as detected with an immunoperoxidase staining and immunofluorescence flow cytometric analysis using monoclonal antibodies. Their expression was induced during a 7-day incubation period with gamma-interferon. These findings suggest that a possible mode of action of the preservation methods of cartilage allografts for inducing a prolonged acceptance time is based on the prevention of HLA class II antigen expression by the cartilage cells.

Effect of thyrotropin-releasing hormone (TRH) on the chemiluminescence (CL) activity of human mononuclear cells

The effect of the tripeptide TRH on the chemiluminescence activity of human monocytes was tested. TRH significantly (p less than 0.002) inhibited monocytes activity at pharmacological concentrations of 2 x 10(-4) M/L. The effect was not mediated via Ia or C3a-receptors as was proven by the preincubation of monocytes with the monoclonal antibodies OKIa1 and anti-C3a. Heat inactivation abolished the effect of TRH. This study has demonstrated for the first time, that pharmacological doses of TRH which had already been tentatively employed as a therapeutic agent in men can modulate immunocompetent cells.

[Quantitative CT studies of the lung in an animal experiment model of silicosis]

High resolution, narrow section CT examinations of the lungs were carried out on 21 Javanese macaques (five controls) shortly before the conclusion of 27 months exposure to quartz and/or high pressure. The aim was to establish morphometric CT data for differentiating and quantifying normal and abnormal findings. The results show that the technique has a high sensitivity for demonstrating the pathological lung changes. Final validation depends upon the use of respiratory physiology and biochemical, cytological, and histomorphometric data.

Peripheral blood and intrarenal phagocytic chemiluminescence during acute kidney graft rejection

During organ graft rejection, soluble mediators of inflammation are released into the polymorphs (PMNs) and monocytes recruited from the blood. One functional capacity of polymorphs and monocytes/macrophages is the production of cytotoxic activated oxygen species upon stimulation, which may contribute to the rejection process. Nothing is known about the influence of allograft rejection on this inflammatory cell property. Chemiluminescence (CL) allows measurement of respiratory burst capacity in small cell samples. Zymosan-induced and luminol-amplified CL of diluted whole blood, separated PMNs, and mononuclear cells from peripheral venous blood, as well as of intragraft phagocytes was measured after allogeneic and autologous kidney transplantation in untreated dogs. CL of separated PMNs, mononuclear cells, and intragraft phagocytes was significantly elevated during allograft rejection. In autologous kidneys transplanted to recipients of allografts, CL was also increased in the autologous grafts during rejection of the allogeneic ones, indicating a systemic alteration in phagocyte function.

Monitoring immunocompetent cells in the peripheral blood of stomach cancer patients after splenectomy and gastrectomy

The status of lymphocyte subpopulations in splenectomized (Sx) stomach cancer patients (SCa-patients), assessed by monoclonal antibodies, has not been evaluated so far. Therefore subsets of peripheral white blood cells were monitored prior to and following surgical treatment in gastrectomized (Gx) and Sx (n = 64) as well as in non-Sx patients (n = 39). Postoperative surgical complications were more frequent in the Sx group. However, the 2-year survival rate of this group was higher than in non-Sx patients. Lymphocytes were significantly decreased in both groups of patients during the early postoperative period. Monocytes and polymorphonuclear cells (PMN) increased correspondingly. A significant loss of lymphocytes and their subsets in Sx patients was observed during the 1st-3rd postoperative days as compared to the Gx only patients. The OKT4/OKT8 ratios did not differ in either group of patients, whereas the OKT3+anti-B-Ly2 ratio was significantly increased in Sx patients 1 to 3 days postoperatively.

Palatability and digestibility of soya- and milk proteins in Callithricidae

4 protein sources were tested for palatability, digestibility, influence on bodyweight and consistency of faeces in Callithrix jacchus and Saguinus fuscicollis. The protein sources were incorporated at crude protein levels of 12, 17 and 22% in a pelleted diet. A banana supplement was also fed which reduced the total protein content to 10.7, 14.7 and 18.3%. The test diets, fed for 3 weeks, were well accepted with the milk proteins being slightly preferred. Consumption of the 12% protein pellets was greater than their 22% equivalents. True protein digestibility was calculated to be 97% for lactalbumin, 96% for casein, 90% for soy protein concentrate and 83% for soyabean meal. Changes in bodyweight were negligible. Dry matter of faeces varied between 25% (lactalbumin diets) and 28% (casein diets), but did not change with increasing protein intake. Increasing levels of cellulose, from 2.4 to 7.2% total crude fibre lowered the apparent protein digestibility from 84.3 to 79.2% and the digestibility of dry matter from 82.2 to 76.5%.

Serial evaluation of absolute spleen cell numbers in Lewis lung tumor-bearing mice

Subcutaneous (sc) transposition of the spleen followed by fine needle biopsies (FNB) from the organ allows the evaluation of relative numbers of splenic cells in Lewis lung tumor-bearing mice. Absolute cell numbers (N) can be calculated when the aspirated cells are weighed on a precision balance (m) and counted (c) after resuspension in a defined volume (v): N = C X V/m X M. The weight from the whole spleen (M) is derived from a calibration curve. Splenic nucleated cells and their subsets--as determined by the use of monoclonal antibodies--can thus probably be evaluated with a degree of accuracy which was not possible before. Shifts of splenic cells from and to the organ can be monitored.

Effects of fibre on digestibility and passage time in callithricidae

The effects of fibre in a pelleted diet on food intake, digestibility of crude fibre, dry matter and energy, on passage time and consistency of faeces were studied in 2 species of Callithricidae, Callithrix jacchus and Saguinus fuscicollis. Coarse cellulose, microcellulose, wheat bran and shrimp meal (chitin = crude fibre) were tested in diets containing 2,4 and 6% total crude fibre, respectively. Digestibility and passage time were determined by inclusion of 0.5% Cr2O3 in the diet. Both celluloses had little influence on the digestibility of energy and dry matter. Digestibility of crude fibre was very low. Wheat bran led to evident depression of energy and dry matter digestibility. High digestibility of crude fibre occurred at the higher levels of inclusion in the diet. Shrimp meal was highly digested with little influence on digestibility of energy and dry matter, indicating considerable degradation of chitin. Wheat bran showed a marked effect, while microcellulose had no effect on passage time, consistency and volume of faeces.

Infrared contact coagulation: a new approach for local hyperthermic therapy of solid animal tumors

Infrared contact coagulation (ICC) was evaluated in 3 different tumor models. 56-94% of all tumor-bearing rats, hamsters or mice were cured by ICC, whereas 100% of the controls died. The possibility that long-lasting immunological resistance might develop against the tumor after ICC was investigated by repeated tumor challenge. Cytotoxicity against tumor cells of host thymocytes and splenocytes following ICC was demonstrated in a Winn assay. The production of a mainly T-cell-dependent immune response could be due to ICC-induced antigenic changes in the tumor cells.