The search for human cancer viruses triggered by the discovery of animal tumor viruses in the early twentieth century was unsuccessful until the end of the 1970s, although the concept of oncogenes and tumor-suppressor genes developed by the research on tumor viruses yielded substantial advances in understanding the etiology of cancer. Currently, the advent of molecular biology has led to the identification of seven human viruses as cancer viruses. The histories of tumor virology and the discoveries of human cancer viruses are discussed.
We have studied bone regenerative medicine in order to apply autologous bone marrow stromal cells and platelet-rich plasma as tissue-engineered osteogenic materials. While our studies have been successful to a certain degree, advancing to clinical applications, the strategy for practical use of this method has to be changed because the environment surrounding bone regenerative medicine has evolved dramatically. We have accordingly changed our focus from cells to cell-conditioned media and found that the conditioned medium contains growth factors and matrices released from the cell and promotes regeneration of tissues by recruiting endogenous stem cells and precursor cells, and so we started clinical research based on this finding. However, the amount of regeneration obtained was minimal (millimeters), and reconstruction of segmental bone defects measuring in the centimeter range is still a challenge. We have focused on distraction osteogenesis, which is an excellent model for in vivo tissue regeneration applicable to segmental defects, and have investigated and clarified the mechanisms of distraction osteogenesis at a cellular level based on tissue regeneration processes. Vascularization needs to precede tissue regeneration; therefore, we investigated the strategy for promoting vascularization. A potential approach for enabling tissue regeneration that mimics distraction osteogenesis without using a distraction device is discussed.
Radiation therapy and Sjogren's syndrome cause salivary gland hypofunction, known as xerostomia. Xerostomia remarkably reduces quality of life. This report reviews current studies in basic science and translational research toward treatments for patients suffering from dysfunction and hypofunction of the salivary gland. Here we describe recent researches that have enabled us to understand the mechanisms of salivary gland development and regeneration. In addition, we introduce new approaches to recovering salivary gland function utilizing both gene and cell-based therapy. A good understanding of the mechanisms of salivary gland development facilitates the design of excellent treatments for regeneration and repair of damaged salivary glands.
Sialodochitis fibrinosa is a rare disease characterized by paroxysmal and recurrent swelling of the salivary glands resulting from obstruction of the duct system by fibrinous plugs. Herein, we report the case of a 62-year-old female with sialodochitis fibrinosa of the bilateral submandibular glands with a history of asthma and nasal allergies. A histopathological examination of the fibrinous plugs that extruded from the Wharton's ducts revealed eosinophil accumulation. Blood analyses showed eosinophilia and increased titers of immunoglobulin E. Her symptoms were relieved after the administration of antihistamines and irrigation of the submandibular glands, and recurrence was not observed. These findings suggest the possibility that an allergic trigger was related to the pathogenesis of this case.
Central vein catheterization is an essential method in the treatment of oral and maxillofacial diseases, especially for oral cancers, because an infusion line is sometimes necessary for a long time. Among several veins, the subclavian vein is usually the first choice for catheter insertion in the field of oral and maxillofacial surgery. Although ultrasound guidance is recommended for catheterization, it is occasionally difficult for inexperienced operators to handle ultrasound apparatus. Our department has used an angiographic technique to catheterize into the subclavian vein. So-called "map images" were created to guide the punctate and insert location. Initially, an enhanced image of the subclavian vein was obtained through a digital subtraction angiography (DSA) technique with administration of contrast agent into the subcutaneous vein. This DSA image was overlapped on real-time fluoroscopic images to visualize the vascular distribution of the subclavian vein. Referring to these images (map images), the catheterization could be performed safely and certainly even by inexperienced operators. Moreover, if necessary, ultrasound guidance could simultaneously be used with this method. The method using map images appeared to be a potential tool for sure catheterization into the subclavian vein.