Ultrastructure of macrocellular (large cell) carcinomas of the lung

The electronmicroscopic investigation of five lung tumors histodiagnosed as macrocellular carcinomas showed the ultrastructural monomorphism of large, variedly shaped neoplastic cells, lack of intercellular junctions, voluminous nuclei with many indentations of nuclear membrane, dispersed euchromatin, large and multiple nucleoli, and nuclear bodies. A reduced number of cytoplasmic organelles was characteristic for these cells, represented mainly by mitochondria, rare rough endoplasmic reticulum, free ribosomes rare Golgi vesicles and flattened tubules, and a various amount of tonofilaments. These features characterized the poorly differentiated proliferation forming these tumors. The elements of differential diagnosis from other poorly differentiated lung tumors (epidermoid and cylindrocubic) are discussed, allowing the consideration of this proliferation type with repressed differentiation and maturation as a real one in the framework of lung carcinomas.     

Lung pathogenesis. III. The immunopathogenic component of pulmonary processes (a systemic approach)

The pathogenetic role of hypersensitivity reactions was systemically approached in the framework of chronic lung processes. There were analysed the biphasic evolution at least of this activity (sensitization, hypersensitivity reactions, immunopathogenic mechanisms and the morphological events induced by them having or not an immune significance); these events occurring during the stereotyped dynamics of lung processes, are often repeated, and modify the pre-existing lesions, contributing to the complication and self-perpetuation of lung processes.     

The pathological process. V. Experimental modelling in pathology: general theoretical problems

The theoretical analysis of the characteristic features of pathological processes is being continued with the experimental modelling of the pathological process, with emphasis on gnoseological and heuristic aims. The paper discusses: the compulsory working hypothesis which includes the known and the probable data resulting from the observation of phenomena, the qualities and value of the experimentation for the verification of the working hypothesis, the general features of the experimental modelling in pathology and its purposes, the types of experimental models (simple, two times perturbing and complex) with exemplification and discussion of qualities and limits, the general evaluation and limits of experimental models, the practical elaboration of experimental models with emphasis on the main rational operations, like the choice of animals, of the ways of administration of perturbing agents, of experimental and control lots, of sacrification modalities, as well as the relevance of the experimental results for enlarging the knowledge of the pathological process investigated.     

The pathological process. III(IV). Cellular population systems as substrates of pathological processes: structure, reactivity, dynamics and basic lesions

This fourth paper dealt with the analysis of cellular population systems as the main substrates of pathological processes. The analysis pointed out the reactivity of these systems, their histogenesis and dynamics, their cellular composition and reactional capacity of composing cells, the relations between different groups of cells forming the system (intrasystemic relationships), those between proliferation and differentiation-maturation, the multifactorial determinism of proliferation, differentiation, maturation and mobilization of the cells composing the system. The analysis of basic lesions of cellular population systems (cellular hypertrophy, cell hyperplasia, metaplasia and neoplastic transformation) completed this dynamic investigation.     

The pathological process. II(III). Lesional sequentiality and its multifactorial determining: structure and dynamics of factor ensembles

The dynamic and structural analysis of pathological processes points out their multifactorial determining, the importance of the intrinsic conditioning, the existence of a lesional sequentiality, exemplified by the chain of lesional sequences, morphologically different, the intersequential relations of cohesive and propelling type, and the discontinuity in the progress from one lesional sequence to another. Factor ensembles, ensuring and governing the start of the process and the transition from a lesional sequence to another, were analysed in point of structure, composition, role of substrates, dynamics of ensembles, roles played by ensemble components (cohesive, propelling role).     

In vitro study of low density lipoprotein--collagen interaction

Possibility of LDL--collagen complex formation was investigated in vitro by biochemical assay and electron microscopy. Types I and III collagen isolated from bovine thoracic aorta were incubated with human low density lipoproteins (LDL) at physiological ionic strength, pH and temperature. Biochemical quantification showed that 10-20 micrograms LDL (cholesterol) were bound per 100 micrograms collagen, binding of type III being slightly more pronounced (17%) than that of type I (11%). Binding was in inversely proportional to the extent of fibrillation. The increase of ionic strength and pH reduced the binding, indicating the electrostatic nature of the interaction. These observations suggest a possible trapping mechanism of LDL in the extracellular matrix by means of collagen, which may be relevant for the development of the atherosclerotic lesions.     

Lung pathogenesis. V. The stereotype development of bronchial and lobular pathological reactions (a systemic approach)

Taking into account the present data upon the general stereotyping of different pathological processes of various nature challenged by the extremely numerous environmental actions, a structural analysis of the peculiarities presented by such reactions at the lung level, mainly on bronchial and lobular structures, was attempted. It was shown that the first damaged structures and their behaviour impose the peculiarities of the subsequently developed reactions which manifest a certain stereotyping, different when bronchi or lobules are the first lesioned. Relationships between bronchial and lobular lesions were also analysed and pointed out their role in the development of the whole complex process of the lung. This special aspect of lung complex pathogenesis was also emphasized.