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Background: The aim of this study was to establish a new experimental model to directly analyse the coronary microcirculation in cardiac xenografts. Methods: Intravital fluorescence microscopy (IVM) of the subepicardial microcirculation in heterotopically transplanted hamster-to-rat cardiac xenografts was performed at 30 and 90 min of reperfusion. We quantitatively assessed the microcirculatory perfusion characteristics as well as the interactions of leukocytes and platelets with the endothelium of postcapillary coronary venules in non-sensitised as well as sensitised recipients. Results: In this first experimental IVM study of cardiac xenografts, we successfully visualised the subepicardial microcirculation, i.e. feeding arterioles, nutritive capillaries and draining postcapillary venules, during reperfusion. Leukocyte-endothelial and platelet-endothelial cell interactions could be quantified. In the non-sensitised group, the myocardial microcirculation remained stable during the observation period of 90 min, whereas in the sensitised group, xenografts were rejected immediately. Conclusions: We established a model for the assessment of the microcirculatory dysfunction and inflammation during ischaemia/reperfusion injury in hamster-to-rat cardiac xenografts.

Background. The aim of our study was to investigate the role of inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) production in different stages of murine antigen-induced arthritis (AiA). Methods. Clinical, histological and microcirculatory parameters (measured by intravital fluorescence microscopy) were assessed in the knee joint during acute and chronic AiA after inhibition of iNOS with L-N 6 -(1-iminoethyl)lysine (L-NIL). Plasma concentrations of NO - 2 and NO - 3 were evaluated by the Griess reaction and the expression of iNOS, P- and E-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule I (VCAM-1) by immunohistochemistry. Results. In both stages of the disease, plasma concentrations of NO, and NOR were increased and iNOS was expressed. In the acute phase, swelling, leucocyte adhesion, leucocyte infiltration and expression of adhesion molecules were increased in arthritic animals treated with L-NIL in comparison with untreated arthritic animals. In the chronic phase, no change in the disease parameters could be detected after L-NIL treatment. Conclusion. Increased NO production induced by iNOS during the acute phase of AiA can be regarded as a protective response in the prevention of further leucocytic infiltration and joint destruction, whereas it seems to play a subordinate role in chronic AiA.

The inhibition of angiogenesis might be a therapeutic approach to prevent joint destruction caused by the overgrowing synovial tissue during chronic inflammation. The aim of this study was to investigate angiogenesis in the knee joint of mice with antigen-induced arthritis (AiA) by means of intravital microscopy. Material and Methods: Intravital microscopic assessment was performed in 14 female mice (C57BL6/129SV) on day 8 after AiA induction in two groups (controls, animals with AiA). After preparation of the knee joint under inhalation anesthesia, synovial tissue was investigated by fluorescence microscopy using the plasma marker FITC-dextran (150 kDa). Quantitative assessment of vessel density was performed according to the following categories: “functional capillary density” (FCD, vessels < 10 µm in diameter),“functional vessel density” (FVD, vessels ≥ 10 µm) and FVD of “vessels with angiogenic criteria” (at least one of the following: convoluted vessel, abrupt changes in diameter, unphysiologic branching). After immunostaining of tissue sections with a monoclonal antibody against von Willebrand factor, vessel density (stained endothelium) was quantified as microvessel count/area. Results: There was no significant difference in FCD between the control group (337±9 cm/cm2; mean±SEM) and the AiA group (359±13). However, the density of vessels ≥10 µm in diameter was significantly increased in animals with AiA (135±10 cm/cm2 vs. 61±5 control). Furthermore, the density of blood vessels “with angiogenic criteria” was enhanced in arthritic animals (79±17 cm/cm2 vs. 12±2 control). In addition, there was a significant increase in the “microvessel count” in arthritic animals (297±25 mm-2 vs. 133±16 control). Conclusion: These findings demonstrate that angiogenesis in murine AiA can be assessed quantitatively using intravital microscopy. Further studies will address antiangiogenic strategies in AiA.

Farmer’s lung is a frequent form of extrinsic allergic alveolitis that is induced by inhalation of antigens found in mouldy hay. We have previously shown that in patients with acute episodes of farmer’s lung circulating neutrophils are primed for an enhanced respiratory burst [1]. To further characterize the alveolitis in acute episodes of farmer’s lung, we measured cytokine and endotoxin levels in the bronchoalveolar lavage (BAL) fluid of farmer’s lung patients after inhalative provocation and analysed the expression of leukocyte activation markers and adhesion molecules on both blood and BAL cells pre- and post-exposure.

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.

The following is based on an experimental animal study of Javanese macaques examined by high resolution CT at the end of 27 months exposure to defined amount of quartz and/or high atmospheric pressure [1].

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.

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.

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.

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 Vim 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.

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.