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An ultrastructural and histological study was made to analyse the structural and cellular features of the pulmonary lesions produced in Wistar rats by intraperitoneal (i.p.) administration of cyclophosphamide (two i.p. doses of 150 mg CP/1 kg bw/1 ml PBS). Rats exposed to cyclophosphamide (CP) developed a condition whose morphological picture corresponded to endogenous lipid pneumonia and/or pulmonary alveolar proteinosis-like changes. Damage to the endothelium and neutrophil accumulation in lung vascular bed were found to be potential initiators of endogenous lipid pneumonia-type changes. The possibility of the evolution of the acute lung injury into endogenous lipid pneumonia-type changes and into alveolar proteinosis-like changes was demonstrated. The results of the study supplement the existing theories of pulmonary alveolar proteinosis pathogenesis.

The aim of the present study was the comparative analysis of morphological changes found in the lungs of Buffalo rats in the course of Morris hepatoma 5123 after i.t. treatment with recombinant human TNF-alpha (rhTNF-alpha) and its muteins. Modification of the native TNF-alpha molecule and synthesis of mutagenized analogues can prevent undesirable symptoms observed in the case of therapeutic administration of rhTNF-alpha. TNF-alpha has been shown to interact with two distinct membrane receptors (TNF-R): p55R and p75R. Mutagenized mutein V binds selectively with p55R. Mutein VI fails to recognize either TNF-R. The cytokines were applied in a dose of 10 micrograms protein in a cycle of 8 days. The control group consisted of tumor-bearing animals which were given PBS. Ultrastructural examinations were based on transmission electron microscope (TEM). Mutein VI-receiving animals showed enhanced changes of cytotoxic nature. Severe damage to endothelial cells (necrosis inclusive) was observed. Blood vascular lumen showed accumulation of neutrophils and monocytes. Features of enhanced activity of endothelial cells were noted. Focally, within pulmonary alveoli conglomerates of fibrin and fragments of damaged cells were found, with erythrocytes, neutrophils and macrophages in their vicinity. The epithelium of pulmonary alveoli showed signs of considerable damage, including necrosis. The lumen of pulmonary capillaries in rhTNF-alpha-treated animals showed a predominance of eosinophils and monocytic cells. Features of endothelial stimulation were observed, although without a tendency to form microthrombi. Much less pronounced changes both in the lung capillary bed and in the alveolar epithelial cells were noted in the mutein V-given animals. Our findings confirm the possibility of peripheral activation of cells involved in the cytokine-induced antitumor response. Mutein V with the smallest effect on the lung tissue rebuilding seems to be a rhTNF-alpha derivative which can delimit the undesirable symptoms in the course of antitumor therapy reduced to i.t. injections.

Cyclophosphamide (CP), an antineoplastic and immunosuppressive agent, even when administered in large doses, slightly affects the quantity of blood platelets. The aim of the present study was to analyse the effect of single intraperitoneal administration of CP (150 mg/kg b.w.) on the quantitative changes in platelets obtained from the left and right ventricle of the heart, as well as to evaluate the occurrence of megakaryocytes in lung tissue depending on the period of time that passed from CP administration. In control subgroups, fewer platelets were found in the blood collected from the RV compared with the left ventricle at all time intervals. After 1 and 3 days following i.p. administration of CP, a decrease was observed in the number of platelets both in the blood from the right ventricle and left ventricle when compared with control. However, after 14 days, the number of platelets in the blood from the left ventricle was higher, compared with the left ventricle and right ventricle of control animals, and significantly higher (p < 0.001747), compared with their number obtained from the right ventricle of CP-receiving animals. Simultaneous ultrastructural examinations with transmission electron microscopy revealed the increased number of platelets in the lung vascular bed of CP-receiving rats at all time intervals. However, megakaryocytes were found 7 and 14 days after administration of CP. The findings clearly indicate that the lungs could be a major place of thrombopoiesis following therapy with a single large dose of CP.

An ultrastructural study was made to analyze the structural and cellular features of the pulmonary lesions produced in Wistar rats by the administration of cyclophosphamide (CP) and/or papain (P). Combined administration of cyclophosphamide and papain caused severe damage to lung tissue including necrosis, particularly to alveolar epithelial and endothelial cells. Some of the damaged type II cells showed nuclear and cytoplasmic features that are considered indicative of apoptosis. Apoptosis-like changes were also observed in endothelial and mesenchymal cells in the interstitium of interalveolar septa. Phagocytosis of apoptotic bodies by macrophages was found too. Apoptosis-like changes were not revealed in those areas of lung tissue where fibroplasia processes prevailed. Nor were they observed in the animals receiving papain only. Occasionally apoptosis-like changes were found in type II cells and in endothelial cells in rats given cyclophosphamide only. The results obtained also suggest the possibility of active participation of type II alveolar epithelial cells in the fibroplasia process in the course of lung rebuilding in acute lung tissue damage induced with simultaneous administration of cyclophosphamide and papain.

The present study provides the evaluation of pentoxifylline (PTXF) effect on quantitative and morphological changes of cells isolated from the lungs by BAL method in animals given cyclophosphamide (CP). CP was administered once, intraperitoneally, on the 7th day of the experiment, in a dose of 150 mg/kg b.w. PTXF was administered in drinking water in a dose of 30 mg/kg b.w./24 h for 14 days of the experiment. Morphological examinations of the isolated cells were performed using the scanning electron microscope (SEM). An attempt to identify type II alveolar epithelial cells was also undertaken. A single CP dose caused a significant rise in the total number of cells isolated from the lungs of the animals 7 days following CP administration. At the same time, a fall was noted in the percentage of neutrophilic granulocytes. No significant quantitative changes were observed in the population of cells isolated after 1, 3 and 28 days following CP administration. PTXF, in doses applied, did not significantly affect quantitative changes and morphological picture of the isolated cells. Our observations suggest that none of the methods applied for identification of type II pneumocytes are completely specific. At the same time they stain type II cells and subpopulations of alveolar macrophages heavily loaded with phagocytized surfactant. However, those methods are simple and enable an approximate evaluation of damage and regeneration processes in the extracellular alveolar lining layer and epithelium.

The aim of the study was to evaluate the effect of pentoxifylline (PTXF) on the production of reactive oxygen species in the rat lungs after intraperitoneal (i.p.) cyclophosphamide (CP) administration (150 mg/kg b.w.) and to draw a correlation between the morphological changes and biochemical findings. Morphological examinations were based on ultrastructural analysis in the transmission electron microscope. It was found that single i.p. CP administration caused destructive changes, particularly within mitochondria and lamellar bodies of type II alveolar epithelial cells (EP II), and within blood vessels of interalveolar septa. The changes were accompanied by an increase in the MDA (malondialdehyde) homogenates. The animals receiving PTXF + CP showed normalization of MDA level and minor damage to EP II confined to alterations in lamellar bodies of EP II. The vascular changes observed after i.p. CP administration were manifested in endothelial swelling and accumulation of neutrophilic granulocytes, monocytes and in the later period blood platelets within the capillaries of interalveolar septa. The cells were tightly attached to endothelium. The changes in the vascular system were accompanied by a significant decrease in the activity of antioxidant enzymes (Cu,Zn-SOD and GSSG-R) in the blood serum collected from the left ventricle of the heart. In the animals given PTXF + CP, a higher decrease was revealed in the activity of these enzymes. Ultrastructural examinations found morphological signs of a facilitated flow, mainly of cellular elements, through the vessels of the interalveolar septa of the lungs.

The aim of the present study was the comparative analysis of morphological changes found in the pulmonary microcirculation of pregnant rabbits in the course of experimental septic shock induced by endotoxin or human recombinant TNF-alpha administration. The experiments used 30 female rabbits, white Dutch, c.3 kg mean body weight. The endotoxin Escherichia coli, serotype S.0127: 138 (Sigma) was applied in a single dose of 100 micrograms/kg b.w. intraperitoneally. The human recombinant TNF-alpha (biological activity 2-4 x 10(7) U/mg of protein) was injected intraperitoneally, also once, in a dose of 100 micrograms/kg b.w. Morphological examinations were based on the ultrastructural analysis in the transmission electron microscope. The ultrastructural analysis revealed no morphological differences between pregnant and non-pregnant rabbits which received TNF-alpha. However, significant differences were observed between animals given TNF-alpha and those given the endotoxin. These differences referred to endothelium damage degree and to the cellular composition of inflammatory infiltrations. More severe damage to endothelial cells (necrosis inclusive) was observed in the endotoxin-treated rabbits. Blood vascular lumen in these animals showed cellular aggregation, of neutrophils and platelets in particular as well as microthrombi. An increased tendency towards the development of these changes was noted in pregnant rabbits. The lumen of pulmonary capillaries in TNF-alpha treated animals showed domination of monocytic cells. Features of endothelial cell stimulation were observed, although without a tendency to form microthrombi.

Cyclophosphamide (CP) is one of the widely used cytostatic drugs, with a strong toxic influence on pulmonary tissue. Experimental works have shown that a single high dose of CP causes injury to all elements of the interalveolar septum, especially to the alveolar endothelial and epithelial cells. The aim of this work was to evaluate the influence of pentoxifylline (PTXF) (30 mg/kg b.w.) on the ultrastructure of lungs capillaries and blood cell count as well as plasma fibrinogen levels in Wistar rats after intraperitoneal injection of 150 mg/b.w. CP. We established that in the doses applied PTXF had no statistically significant influence on the number of leukocytes and erythrocytes determined in the left ventricular blood of rats receiving CP, while the number of white cells from animals given PTXF only was higher than in controls. There was a smaller decrease in the number of platelets (p < 0.05) and smaller reduction in fibrinogen level (p < 0.01) in the serum of PTXF-CP animals than in the CP group. The results obtained suggest a protective effect of PTXF on CP induced changes, which have been evidenced in some of the parameters examined. Ultrastructural examinations found the lungs to be the organ of extramedullary thrombocytopoiesis in CP-treated animals and revealed that platelet accumulation in the system of lung capillaries was a potential cause of the decrease observed in the number of blood platelets following CP administration.

The aim of the paper was to evaluate mutual relations in the system of alveolar macrophage (AM) - type II pneumocyte (PII) - interstitium of alveolar septa, in the course of experimental lung emphysema in rats subjected to BCG vaccine effect. Administration of BCG vaccine resulted in the cumulation of AM within pulmonary alveoli. These cells exhibited morphological features of increased activity. Intratracheal papain injection induced intralobular emphysema changes, partly generalized, in the animal lungs. The emphysematous changes, with domination of interalveolar septum atrophy, were accompanied by focal accumulation of collagen and elastin. Fibroplasia processes were strongly pronounced in BCG- and papain-treated animals. The areas of connective tissue fibres cumulation revealed indistinctness of the boundary line between PII and the interstitium in some places. Anchorage of collagen fibres and microfibrillary structures were observed in the cytoplasm of PII. The morphological examinations of AM - fibroblasts co-cultures as well as the evaluation of the uptake of 3H-thymidine did not show any significant differences between respective co-cultures of fibroblasts and AM isolated both from the lungs of control and experimental animals (treated with BCG or papain, and BCG+papain). However, a significant growth was noted in 3H-thymidine uptake between fibroblast cultures realized with or without cells isolated from the lungs. The results obtained suggest the possibility of active participation of PII and AM in fibroplasia processes in the course of lung rebuilding after papain administration and in pathological states of the pulmonary tissue, particularly when they are accompanied by increased activity of alveolar macrophages. They also support the inflammatory-repair hypothesis in the development of emphysematous changes.

The effect of macrophage system activation on the intensity degree of early destructive changes induced with intratracheal infusion of a proteolytic enzyme-papain was evaluated in the paper. The study was carried out on male Wistar rats. BCG vaccine was used as a macrophage system activating substance. Damage degree of the pulmonary tissue was evaluated after 2 hours following papain administration by determining W/D index (wet lungs/dry lungs). Spectrophometric analysis of bronchoalveolar lavages (BAL) was made in order to evaluate the advancement of haemorrhagic alterations in the lungs. Damage to the pulmonary tissue was greater in the animals given BCG vaccine and papain, compared with controls and papain treated animals. Differences in the intensity degree of destructive changes assessed using both the W/D index and haemoglobin content in BAL were statistically significant. The results obtained indicate a particular role of activation of the macrophage system in the development of early destructive changes due to intratracheal administration of proteolytic enzymes and point to the significance of these changes in the morphogenesis of experimental lung emphysema.

We analysed the effect of rhTNF-alpha on the development of Morris hepatoma 5123 spontaneous metastases to the lungs of Buffalo rats. After intratumour administration of the cytokine the lungs were found to contain scarce metastatic foci. In precapillaries and capillaries neoplastic cells were single or in small clusters, without contact with endothelial cells. Endothelial cells showed high pinocytic activity and frequently tightly closed vascular lumen. The stroma of interalveolar septa and the capillary bed contained multiple eosinophils. Moreover, eosinophils, histiocytes and monocytes mixed with abundant collagen fibres were found on the margin of single small metastatic foci and among necrotic neoplastic cells.

The studies were performed basing on the experimental model of acute pulmonary tissue injury. Papain in a dose of 2 mg/ml PBS/100 g b.w. was administered once, intratracheally, on the 21st day of the experiment. Besides, female Wistar rats were injected twice with BCG vaccine in a dose of 4 x 10(8) microorganisms. BCG vaccine was administered intraperitoneally on the 1st and 14th day of the experiment to activate the system of mononuclear phagocytes. Control rats were intratracheally or/and intraperitoneally given PBS solution. All the animals were killed on the 28th, 35th and 42nd day of the experiment. A single intratracheal papain injection induced emphysematous changes in the animal lungs. The changes were accompanied by basement membrane rebuilding and focal collagen and elastin cumulation. An increase in the number of type II alveolar epithelial cells was observed. Anchorage of collagen fibres and microfibrillary structures in the cytoplasm of type II pneumocytes was observed in the BCG- and papain-treated animals. There, the cytoplasmic membrane of type II cells was completely indistinct and the cytoplasm formed processes to penetrate into the connective tissue fibres. The results obtained indicate possible contribution of type II pneumocytes to fibroplasia processes during lung parenchyma rebuilding and suggest the necessity to include fibroplasia elements in the existing definition of emphysema.

Ultrastructural analysis was made of the pulmonary capillary endothelial cells, with special regard paid to their possible contribution to the processes of pulmonary tissue rebuilding initiated by intratracheal infusion of a proteolytic enzyme-papain. Experimental animals (male Wistar rats) were additionally given BCG vaccine in doses activating the alveolar macrophage system. The study was performed after 1 day, and 1, 4 and 12 weeks following papain administration. In the animals given BCG vaccine, ultrastructural exponents of endothelial cell activation were found. Cumulation of inflammatory cells, mainly monocytes, was observed in vascular lumen. Application of papain solution to animals caused a number of damaging and exudative changes, being most pronounced within vascular endothelium in animals simultaneously given BCG vaccine. In later periods, rebuilding and productive processes, accompanied by collagen cumulation in the interstitium of interalveolar septa, dominated. In the animals receiving BCG vaccine and papain, ultrastructural pictures indicated active contribution of endothelial cells to the processes of pulmonary tissue rebuilding initiated by intratracheal infusion of the proteolytic enzyme.

Processes which occur within the capillaries of interalveolar septa play a major role in many lung diseases. In the present study, ultrastructural analysis of pulmonary capillaries was made at 7 days after intratracheal instillation of a proteolytic enzyme - papain, that is when macrophage cumulation within pulmonary tissue was maximal. Experimental animals (male Wistar rats) were injected with BCG vaccine, in doses that would stimulate the macrophage system to produce TNF-alpha. All the experimental groups, compared with the control, showed cumulation and increased adherence of monocytes, granulocytes and blood platelets to endothelium. Changes within endothelial cells manifesting their activation were observed. In the animals receiving papain or BCG, focal destruction of endothelial cells was found. The picture of vascular changes induced with papain and by simultaneous stimulation with BCG vaccine revealed a number of features similar to those found in the adult respiratory distress syndrome. The study proved usefulness of vascular perfusion as a method to analyze the vascular system, particularly in the processes progressing with activation and increased adhesion of inflammatory cells to the endothelium of pulmonary capillaries.

Selected morphometric parameters of the lungs and heart of rats with experimental emphysema caused by a proteolytic enzyme--papain have been presented. The morphometric evaluation was carried out after the 1st, 3rd and 6th months following an intratracheal infusion of papain solution. It was found that administration of the papain caused emphysematous changes in the lungs, which intensity measured morphometricly increased until the third month, and then became stable. The first evidence of the right ventricle hypertrophy appeared already in the third month of the experiment. The evident hypertrophy of the muscle of both ventricles and of the interventricular septum was observed after six months of the experiment. Morphologic changes developing in both ventricles suggest an existence of a common pathogenetic factor affecting simultaneously the myocardium of right and left heart ventricles.

In the last years pentoxifylline (PTXF) has been successfully used in reducing acute injury of the lung parenchyma in ARDS. The authors have studied the effect of PTXF on degree of papain induced lung injury. Papain was administered intratracheally in a dose of 2 mg, 4 mg, 6 mg in 1 ml of PBS. The effect of papain on bronchoalveolar lavage characteristics was also evaluated. Wistar rats of both sexes were used in the experiment. The degree of lung destruction, reflected by interstitial hemorrhage was assessed by measuring hemoglobin content in the fluid of the lavaged lungs. The hemoglobin levels were assessed spectrofluorometrically with the use of the 414 nm wave length. A reduction of hemoglobin content was seen after PTXF administration only in animals receiving the lowest dosage of papain. However in all animals a decrease in the BAL neutrophil count was demonstrated. The protective effect of PTXF on pulmonary tissue in papain induced injury models and situations leading to development of ARDS may suggest a similar pathomechanism in both entities.

The study was carried out on an experimental papain induced model of pulmonary emphysema. The authors assessed the cell populations sampled with lavage. Special emphasis was directed on alveolar macrophages and neutrophils. Extent of emphysema was analysed morphometrically. The authors demonstrated an influx of neutrophils 24 hours after papain was introduced intratracheally. This was followed by a swift decrease of the number of sampled neutrophils. Seven days latter the neutrophil count returned to normal. A significant increase of alveolar macrophages was seen on the seventh day. The increased macrophage count correlated with the extent of the pulmonary emphysema destruction.