Kimihiko Takusagawa

Electron microscopic observations on pulmonary connective tissue stained by Ruthenium Red

SummaryUltrastructural studies on human lung were performed with special attention to the interstitial acid mucopolysaccharides by Ruthenium Red staining and several enzyme digetion tests withStreptomyces hyaluronidase, chondroitinase ABC, chondroitinase AC, heparinase, trypsin and collagenase.Periodic lateral granules on the major cross bands of collagen fibrils and amorphous coats on them became visible by Ruthenium Red staining. The surface of elastic fibres, associated microfibrils, and some fine fibrils 10–20 nm in diameter were stained. Ruthenium Red also stained the surface of fibroblast and smooth muscle cells, basement membrane and filamentous long segments. In the interstructural space, granular substances 10–80 nm in diameter and fine filaments 3–4 nm thick, which formed a fine reticular network, were clearly observed. They were not visible on the usual thin section. The granular substances were located on the cross points of the fine filaments. They spread continuously and connected with each of the cells and extracellular structures in the pulmonary interstitium. The results of the enzyme digestion tests on the Ruthenium Red-positive material are discussed.

Ultrastructure of the lewis lung carcinoma

ELectron microscopic observations were made on the Lewis lung carcinoma, which has frequently been used in various experiments. Although the tumor cells had desmosomes, interdigitation, microvilli and basement membranes which were of epithelial nature, they did not show either squamous or adenomatous differentiation. On the basis of microscopic and ultrastructural findings, this tumor falls into the category of large cell carcinomas. At the periphery of the tumor, sinusoidal clefts between the strands of tumor cells contained many red blood cells without fibrin. While perfect blood vessels were observed towards the center of the tumor, large necrotic areas were observed. Dilated large vessels possessed some endothelial fenestrations. Light endothelial cells were also observed, which were penetrated by red blood cells. Interstitial components were very scant and collagen fibres were frequently observed to be dissolved.

Conversion of Lewis Lung Carcinoma into Ascitic Form

Lewis lung carcinoma (3LL), which has been most frequently used for various investigations of cancer, was converted to an ascitic form designated 3LL-SA. Ascites tumor cells showed a mixed population of single cells and about 10% islands which were made up of 2 to about 50 cells. Transplantability was 100%. The biological and metastatic capacities were preserved in this line as shown by its ability to form hemorrhagic and necrotic tumors, and by its multiple lung metastases. Moreover, histological and ultrastructural characteristics of this tumor line were identical to those of the parental 3LL. Thus, it can be seen that 3LL-SA will be a useful tool for the study of cancer.

Pattern of fibronectin distribution in human lung cancer.

SummaryThe pattern of fibronectin (FN) distribution in human lung cancer was studied by indirect immunofluorescent staining, and by the peroxidase-antiperoxidase method in a total of 60 surgical specimens. They comprised 8 small cell carcinomas, 4 large cell carcinomas, 19 squamous cell carcinomas, 28 adenocarcinomas, and 1 adenoid cystic carcinoma.Of the 60 specimens 13 were FN-positive. They included 4 large cell carcinomas, 4 small cell carcinomas, 3 poorly differentiated squamous cell carcinomas, and 2 poorly differentiated and 1 moderatety differentiated adenocarcinomas.On the other hand, none of the well differentiated carcinomas was FN-positive around tumor cells. Our data suggest that undifferentiated, or poorly differentiated carcinomas of the lung tend to be FN-positive.

Abnormal cilia in the small airways of mice induced by bleomycin.

The frequency and types of abnormal cilia in the small airways before and after parenteral administration of bleomycin were examined by transmission electron microscopy. Bleomycin was injected subcutaneously at a dose of 40 mg/kg twice weekly for 6 weeks. Bronchioles less than 0.1 mm in diameter from animals sacrificed 1 day after a single dose, 1 day after three doses, 3 days after 8 doses, and 13 days after 12 doses were selected for evaluation. Although ciliated cells proper did not show pronounced alterations, abnormal cilia such as swollen cilia, compound cilia, and cilia with abnormal axonemes frequently occurred. Repeated injections did not necessarily induce much more abnormal cilia than one dose. The results suggested that ciliated cells remain undamaged and that normal cilia can be restored. The specific type of abnormal cilia induced by bleomycin was not identified.