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H Redl

Publications and source records attributed to H Redl.

At least 199 records · Page 11Linked to original sources

Morphology of the microvascular system in shock: lung, liver, and skeletal muscles.

We used a standardized canine polytrauma model (bone fracture, soft-tissue injury, and hypovolemia), either with or without reinfusion, to study granulocyte accumulation in lung, liver, and muscle tissue. Infusion of radioactively labeled granulocytes revealed significant leukostasis in the lung after the shock procedure, which was more prominent in the group without reinfusion. There was only moderate leukostasis in the liver, while granulocytes were absent from muscle tissue. These radioactive data were in good agreement with the morphologic findings of electron microscopy. Thus, although there was capillary endothelial swelling in all three organs, edema in the muscle endothelial cells of reperfused animals was not due to granulocyte action.

Animals↗

[Influence of parenteral nutrition on phospholipid metabolism in the rat lung in the posttraumatic period].

Most experimental studies in the field of parenteral nutrition following trauma are aimed at a reduction of catabolism and therefore an improvement of the N-balance. The aim of this study was to investigate the influence of PN on PHL composition in the posttraumatic lung, especially in the surfactant fraction. We compared a carbohydrate - amino acid formula with a formula containing carbohydrate - amino acid - lipid. Polytrauma was performed by single femur fracture plus laparotomy with eventeration of the intestines for 30 minutes and hypovolemia (2 ml/100 g bw). After an adaption phase with reduced caloric supply, full caloric support was given from the 4th to the 14th day (100 Kcal/kg bw/day). The following metabolic parameters were used: N-balance; phospholipid total, -classes, -molecular species and fatty acid pattern of lecithin in lung tissue and lavage (using special HPLC and GC techniques). There were small differences between the groups using standard metabolic parameters (such as nitrogen balance). In contrast, we found significantly altered phospholipid patterns in the lung. With lipid emulsion there was an increased fraction of saturated lecithins (mainly dipalmitoyl phosphatidylcholine). From our data we conclude that it is possible to influence surfactant phospholipid composition by parenteral nutrition through the use of lipid emulsion. This might be useful for posttraumatic lung treatment.

Animals↗

Quantitative assessment of leukostasis in experimental hypovolemic-traumatic shock.

Using a hypovolemic-traumatic shock model without reinfusion of shed blood, 111In-oxine-labeled granulocytes were injected to quantify pulmonary leukostasis in dogs. Labeling was facilitated by a non-traumatic and rapid technique for granulocyte processing and a commercially available 111In-oxine solution. Lung biopsy material taken before and after shock showed granulocyte-associated radioactivity to be significantly increased 90 min after the onset of shock. This observation established that pulmonary leukostasis in shock models is not caused solely by reinfusion of shed blood, but rather by humoral factors operative during shock, e.g. by complement activation. The described experimental design should also be useful for in vivo tests of drugs which act on granulocyte function and may have a potential place in the management of shock.

Animals↗

Red cell count dependence of whole blood granulocyte luminescence.

To evaluate phagocytosis of granulocyte, chemiluminescence (CL) - measurements were done in whole blood specimen. By this method much less variation (22% versus 84%) could be achieved in the whole blood specimen compared with isolated granulocytes. The quenching of CL by erythrocytes, which is dependent on the quotient erythrocytes/granulocytes, could be significantly reduced by dilution (1:5,000). Optimized reaction conditions were selected (approx. 5 x more sensitive then previous protocols) to evaluate the phagocytic activity of the few remaining granulocytes (approx. 2,000/ml) with routine luminometers.

Erythrocyte Count↗

Comparative evaluation of immunhistochemistry and enzyme histochemistry for granulocyte visualization in formalin-fixed and paraffin-embedded liver and lung biopsies.

Two methods for the specific visualization of granulocytes (PMNs) in formalin-fixed and paraffin-embedded tissue samples were compared: (1) the well-established enzyme histochemical method using naphthol-AS-D-chloracetate as a substrate; (2) an immunoperoxidase reaction using anti-PMN serum. Both methods are highly selective for visualizing PMNs. The advantages offered by the immunohistochemical method, i.e. better visualization of the remaining tissue structures and potential combination with other staining techniques, are stressed. Problems of PMN visualization in lung tissue and effects of tissue preparation are discussed. For histomorphometric studies the immunohistochemical method is preferable.

Animals↗

Aggregation, chemotaxis, and chemiluminescence of canine granulocytes. Studies utilizing improved cell preparation techniques.

Wishing to extrapolate in vitro observations of granulocyte function and pharmacology made with human cells to animal models of diseases in which we believe granulocyte stimulation to play a major role, we examined techniques for preparation of canine granulocytes and conducted a survey of the function and pharmacology of those cells. Isotonic density gradients of Percoll proved a simple and highly satisfactory method of preparation. Canine granulocytes in most respects paralleled human cells in function and pharmacology, except that canine cells lacked receptors for formylated oligopeptides and resisted them as stimuli; canine plasma contained a heat-labile inhibitor of canine PMN aggregation, oxidative metabolism, and myeloperoxidase release; canine PMNs were not inhibited in aggregation by protease inhibitors such as aprotinin; canine response to ibuprofen and steroids was more variable than that of human cells, and synergy between those agents was less readily demonstrated; heterologous stimulation (canine cells by human C5a or vice versa) led to a different time course and maximum response from those observed in the homologous systems. Canine granulocytes were readily marked with indium-111, and functioned normally in vitro and survived well in vivo after marking. We conclude that the dog is a suitable animal for studying the role of stimulated PMNs in disease, as long as the observed differences are taken into account in experimental design and data interpretation.

Animals↗

In vitro properties of mixtures of fibrin seal and antibiotics.

The incorporation of gentamycin, neomycin and Polymyxin E into fibrin seal results in prolonged clotting time after mixture with 4 NIH-units of thrombin per ml in vitro. The aminoglycoside antibiotics gentamycin and neomycin also diminished fibrin-alpha-chain crosslinkage and, as a consequence, clot rigidity, as demonstrated with clots containing gentamycin. Clotting time and the rate of alpha-chain crosslinking can be adjusted to normal values by the use of higher thrombin concentrations and incorporation of additional factor XIII into the sealing system. Drug release from the clots was similar for all three antibiotics tested and mainly dependent on the concentration gradient between the clot and its environment. Under the conditions of the present study, about 85% of the antibiotic content of fibrin seal clots were released within 72 h.

Anti-Bacterial Agents↗

Augmentation by platelets of granulocyte aggregation in response to chemotaxins: studies utilizing an improved cell preparation technique.

Considerable evidence exists to suggest roles for both platelets and granulocytes (PMNs) in pulmonary injury in shock. While believing that the major contributions of the two cell types are sequential, in vitro observations suggested that direct interactions between granulocytes and platelets might also amplify tissue damage. Using isotonic Percoll density gradients to isolate PMNs, we therefore studied the effect of deliberate platelet contamination on PMN aggregation. PMN aggregation in response to N-formyl-met-leu-phe or activated complement was enhanced by the presence of 1 platelet/PMN, an effect that became maximal at 16 platelets/PMN (p less than 0.01); large mixed aggregates were formed. Lysed, aspirinated, and indomethacin-treated platelets retained their augmentative capacity, as did platelets washed by gel filtration. The effect was not mimicked by the addition of histamine or serotonin to PMN preparations. None of these platelet preparations augmented lysosomal enzyme release. We conclude that platelets augment PMN aggregation, both by forming giant mixed PMN/platelet aggregates and also by producing a labile augmentative substance, the production of which may be independent of thromboxane synthesis. We propose that direct as well as sequential platelet/PMN interactions may be important in tissue injury in shock.

Blood Platelets↗

Methods of fibrin seal application.

With the help of various tests (tensile strength, distribution in cancellous bone blocks, thrombin release from standard clots), the importance of mixing the solutions of the fibrin sealant system was demonstrated and an optimal mixing ratio of one to one was identified. Different application techniques are discussed. The spraying technique, which produces rapid hemostasis, is reviewed in detail. As further advantage, the resulting sealant film is thin. This appears important for promoting wound healing.

Animals↗

[In vivo and in vitro degradation of fibrin adhesives (studies in rats)].

The fibrin seal (FS) is of indisputed value for hemostasis and atraumatic tissue synthesis in surgical therapy. In order to determine the optimal FS composition for resistance against fibrinolysis, in vivo lysis was tested by adding increasing amounts of the fibrinolysis-inhibitor aprotinine to 125I FS; urokinasis and plasminogen were administered in vitro while measuring protein and 125Iodine release. The correlation of protein and 125Iodine release clearly reflects the interdependence of both parameters; disjunction of radioactivity from the protein molecule was ruled out. In vitro, fibrinolysis is inhibited to a nearly unlimited extent by aprotinine. In vitro, aprotinine improves fibrinolysis inhibition only up to a maximum of 1500 KIE/ml clot, thereby significantly altering the maximum elimination of 125Iodine and FS half-life as well. Higher doses of aprotinine applied in vivo remain without effect upon FS stability. In human surgery, the addition of aprotinine to FS is recommended for strictly hemostyptic application only, but not for tissue synthesis such as nerve- and microvessel-anastomoses in plastic reconstructive surgery.

Animals↗

[Immuno and enzyme histochemical demonstration of granulocytes--assay of a morphometric evaluation].

Using the naphthol AS-D-chloroacetate esterase method and the indirect immunoperoxidase technique we tried to stain selectively granulocytes in the lung and in the liver. For the immuno technique we used an antibody raised in rabbits against dog granulocytes, which were prepared by a new separation technique. Comparing the two staining methods we found the immunoperoxidase to be superior at least for quantitative evaluation. In a pilot study with polytraumatized dogs versus controls we could detect a more pronounced leucostasis within the trauma group. This was similar to a parallel study which used radioactive labeled granulocytes where a significant increase could be shown. Granulocytes, at least in part, seem to be important for cellular changes within the "lung in shock".

Animals↗

[New aspects of the shock lung (author's transl)].

Using intravital lung biopsies and a shock model, which is based on preceding ultrastructural studies in humans, we could detect leucostasis and swelling of endothelial cells as a sign of the "lung in shock". These events are responsible for the resulting irreversible lung deterioration, though they are not accessible to clinical diagnosis. Therefore one must perform prophylactic treatment such as artificial ventilation, pharmacological influence on granulocyte functions including the release of lysosomal enzymes und oxygen radicals. In this way ARDS must be avoided, because there is still a mortality of about 60% with this syndrome.

Complement C5↗

[Lung-converting-enzyme as a possible cell-maker in connection with the ultrastructural morphology in hypovolemic-traumatic shock (author's transl)].

The lung shock syndrome, associated with a high rate of mortality, has been tested on an experimental animal model and was compared with clinical results. Consequently we obtained specimens as a base for morphologic examinations and LCE-determinations. A modified flurometric method to determine the angiotensin-converting-enzyme (LCE) has been developed. As a consequence a significant increase of the LCE-activity in shock also was noticed which might have been caused by the damage of the endothelial cells. The main part of this enzyme is situated on the surface of the lung endothelial cells and could be used as a marker enzyme.

Animals↗

Electron-microscopic investigation of lung biopsies in patients with post-traumatic respiratory insufficiency.

Lung biopsies were taken from patients during the course of post-traumatic respiratory insufficiency, from 3 hours to 19 days after the onset of shock. Electron-microscopic investigations revealed that the initial phases of cellular damaged were followed by both endothelial and epithelial changes, including atelectasis, lymphatic dilation, and interstitial as well as interalveolar fibrin extravasation. Interstitial edema and extravascular migration of granulocytes, lymphocytes and mast cells are followed by fibroblastic proliferation and, as an end result, fibrosis of the alveolar septa. As a result, fibroblasts replace capillaries at the surface, where gas exchange takes place. The capillaries are forced into the depths of the interstitial tissues. At the same time, the alveolar surface becomes covered with thick-walled proliferating epithelial cell layers, which also renders gas exchange increasingly difficult. Lung function is thereby reduced.

Endothelium↗

[Acute post-traumatic lung failure - morphological evaluation (author's transl)].

We investigated morphological findings of human biopsy material taken from lung and muscle, as well as lung tissue taken from animals in hypovolatemic-traumatic shock experiments. This was an attempt to reproduce, by way of an experimental setup with animals, the morphological changes which were formely found in the biopsies. Our morphological results lead to the assumption that the posttraumatic progressive lung failure without direct lung trauma can be divided into two major phases which are of decisive importance for the clinical development. 1. Early changes: Massive leucostasis of polymorphonuclear granulocytes with partial degranulation in the lung. In additon, a swelling of the endothelium cells, fat globules and a beginning interstitial edema were observed. In none of the cases were microthrombi found. 2. The actual "shock lung or fat embolism syndrome" which can be diagnosed also clinically 24 to 72 hours after the trauma. Morphologically predominating here are the interstitial edema and the fibrosis secondary to this and which manifests itself clinically in a disturbed gas exchange. This is accompanied by serious changes in the alveolar epithelium, deposits rich in protein as well as an increased occurence of phagocytizing macrophages in the alveoli. The early morphological changes in shock lung can most likely be influenced by therapeutical measures (such as a prompt shock treatment, a balanced restoration of the loss in blood volume and an early artificial ventilation). In this way, also the feared shock lung syndrome can be avoided. In an experimental setup with animals these early changes, especially the leucostasis, can easily by reproduced. This has become possible by the experience gained from the human lung biopsies. By way of this animal experiment new methods of treatment can be tested which might lead to a clinical progress in the prophylaxis as well as in the treatment of the progressive post-traumatic lung failure.

Animals↗

[Leucostasis in the lung during hypovolemic-traumatic shock (author's transl)].

The cause of the posttraumatic respiratory distress syndrome is not yet well known and cannot be proved with certainty. The early stage of posttraumatic lung failure has been examined both from a morphological and biochemical aspect. Lung biopsies taken during hypovolemic-traumatic shock show besides endothelial damage an accumulation of leucocytes with free granules, similar to lysosomes. Based on these results further tests have been carried out to achieve a similar reaction in the hypovolemic-traumatic shock model in the dog, enabling us to undertake more extensive examinations and to use new methods of treatment. The lung biopsies taken at the beginning and after finishing the test were observed by light-transmission and scanning electron-microscope. Similar to the results obtained from humans, we found a massive leucostasis with degranulated cells. A parallel increase of lysosomal enzyme activity and a peripheral leucocytosis was seen while after reinfusion a distinct decrease was found. The massive occurence of leucocytes in the lung may be caused either by chemotaxis or by the sieve function of the lung after peripheral leucocytes aggregation. Both could have an immunological cause, especially due to involvement of the complement system. Septic reasons in the early stage of shock can be disregarded. More likely the complex effects of the interactions complement--fibrinolysis--kallikrein system are involved. Presumably the leucocytes caused direct damage to the endothelial cells. Lysosomal enzymes as reason for producing the damage would be one possibility; an other is the recently discovered effect of oxygen radicals produced during the close contact between leucocytes and endothelium and the simultaneously activated complement system.

Acid Phosphatase↗