Application of electron microscopic radioautography to clinical electron microscopy

Radioautographology general and special

A new concept, termed "radioautographology" is advocated and its contents are reviewed. This term is the coinage synthesized from "radioautography" and "(o)logy", expressing a new science derived from radioautography. The concept of radioautographology (RAGology) is a science to localize the radioactive substances in the biological structure of the objects and to analyze and to study the significance of these substances in the biological structure. On the other hand, the old term radioautography (RAG) or autoradiography (ARG) is the technique to demonstrate the pattern of localization of various radiolabeled compounds in biological specimens. The specimens used in biology and medicine are cells and tissues. They are fixed, sectioned and made contact with the radioautographic emulsions, exposed and developed to produce metallic silver grains. Such specimens are designated as radioautographs (or autoradiographs) and the patterns of pictures made of silver grains are named radioautograms. Those people who produced radioautographs were formerly named radioautographers (or autoradiographers) who were only technicians, while those who study RAGology are not technicians but scientists and should be called as radioautographologists. The science of radioautographology was developed in the 20th century and can be divided into two parts, general radioautographology and special radioautographology, as most natural sciences usually can. The general radioautographology is the technology of RAG which consists of 3 fields of sciences, physics concerning radioactivity, histochemistry treating the cells and tissues and photochemistry dealing with the photographic emulsions. The special radioautographology, on the other hand, consists of applications of general radioautographology to various biological and medical sciences. The applications can be classified into several scientific fields, i.e., cellular molecular biology, anatomy, histology, embryology, pathology and pharmacology. Studies carried out in our laboratory were summarized and reviewed. The results obtained from the technology includes 4-dimensional structures of the organs taking the time dimension into account by labeling cells and localizing the sites of incorporation, synthesis, discharge of the labeled compounds in connection with the time lapse and aging of animals. All the results obtained from such applications should be systematized as a new filed of science in the future in the 21st century.

Special cytochemistry in cell biology

Cytochemistry is a science of localizing chemical components of cells and organelles on histological sections by using various techniques. We first aimed at studying cytochemistry by developing new techniques using various principles such as enzyme cytochemistry, microincineration, microspectrophotometry, radioautography, cryo-techniques, X-ray microanalysis and immunocytochemistry. We first concentrated on developing methodologies in the 1960s to 1970s. We then applied these special techniques to various kinds of cells in men and animals. Earlier, I proposed to classify these methods into three categories, i.e., chemical, physical, and biological techniques. The methodology has been well developed to form a new science which should be designated as "general cytochemistry" similarly to the general histology. On the other hand, these techniques should be applied to various cells in various organ systems, such as the skeletal, muscular, digestive, respiratory, urinary, reproductive, endocrine, circulatory, nervous and sensory systems similarly to the special histology or the histology of organs. I summarize the results of cytochemical studies on cells of various organs carried out in our laboratory during these 44 years since 1955. The results obtained from cytochemical studies applied to various cells in respective organ systems should be designated as "special cytochemistry."

Radioautographology: the proposal of a new concept

A new concept termed "radioautographology" is advocated. This term was synthesized from "radioautography" and "ology", expressing a new science derived from radioautography. The concept of radioautographology (RAGology) is that of a science whose objective is to localize radioactive substances in the biological structure of objects and to analyze and study the significance of these substances in the biological structure. On the other hand, the old term radioautography (RAG) is the technique used to demonstrate the pattern of localization of various radiolabeled compounds in specimens. The specimens used in biology and medicine are cells and tissues. They are fixed, sectioned and placed in contact with the radioautographic emulsions, which are exposed and developed to produce metallic silver grains. Such specimens are designated as radioautographs and the patterns of pictures made of silver grains are named radioautograms. The technicians who produce radioautographs are named radioautographers, while those who study RAGology are scientists and should be called radioautographologists. The science of RAGology can be divided into two parts, general RAGology and special RAGology, as most natural sciences usually can. General RAGology is the technology of RAG which consists of three fields of science, i.e., physics concerning radioactivity, histochemistry for the treatment of cells and tissues, and photochemistry dealing with the photographic emulsions. Special RAGology, on the other hand, consists of applications of general RAGology. The applications can be classified into several scientific fields, i.e., cellular and molecular biology, anatomy, histology, embryology, pathology and pharmacology. Studies carried out in our laboratory are summarized and reviewed. All the results obtained from such applications should be systematized as a new field of science in the future.

A light and electron microscopic radioautographic study on RNA synthesis in the retina of chick embryo

The incorporation of 3H-uridine into RNA of chick embryo retina was studied by light and electron microscopic radioautography. The numbers of silver grains were counted over the nucleus, nucleolus and cytoplasm of the cells in three different regions of the same retina of 2, 3, 4, and 7 day chick embryos. The results showed an increase of 3H-uridine incorporation from embryonic day 2 to 7. In every stage of development of the chick embryo retina, the number of silver grains was higher in the anterior than in the other two regions of the retina. In the three cell compartments of every embryo group, the number of silver grains was higher in the nucleus than in the nucleolus and cytoplasm. The results show further that the grains were less in the cytoplasm of the retinal cells of the day 2 embryo group and higher in the other groups especially in the day 7 embryos. Ultrastructural changes were also observed during the studied period of retina development.