The role of telomerase activation in the regulation of vascular smooth muscle cell proliferation

Telomeres are primarily controlled by a highly specialized DNA polymerase, termed telomerase. In early studies, high levels of telomerase activity were detected in cancer cells, but no activity was found in most normal somatic cells, leading to the speculation that telomerase might be required for tumor growth. Recent studies have demonstrated that introduction of the telomerase catalytic component (TERT) into telomerase- negative cells activates telomerase and extends cell lifespan, whereas mice lacking telomerase activity revealed impaired cell proliferation in some organs as well as reduced tumorigenesis. These findings suggest that telomerase plays an important role in long-term cell viability and cell proliferation. We have recently demonstrated a crucial role of telomerase activation in the regulation of vascular smooth muscle cell (VSMC) proliferation and clarified the mechanisms by which telomerase is activated in the process of VSMC growth. Moreover, increasing evidence suggests that telomerase activity contributes to the vascular pathophysiology. Thus, further understanding of the role of telomerase and telomere function would provide new insights into the treatment of human vascular disorders.     

Feldkamp-based cone-beam reconstruction for gantry-tilted helical multislice CT

Depending on the clinical application, it is frequently necessary to tilt the gantry of an x-ray CT system with respect to the patient and couch. For single-slice fan-beam systems, tilting the gantry introduces no errors or artifacts. Most current systems, however, are helical multislice systems with up to 16 slices. The multislice helical reconstruction algorithms used to create CT images must be modified to account for tilting of the gantry. If they are not, the quality of reconstructed images will be poor with the presence of significant artifacts, such as smearing and double-imaging of anatomical structures. Current CT systems employ three primary types of reconstruction algorithms: helical fan-beam approximation, advanced single-slice rebinning, and Feldkamp-based algorithms. This paper presents a generalized helical cone-beam Feldkamp-based algorithm that is valid for both tilted and nontilted orientations of the gantry. Unlike some of the other algorithms, generalization of the Feldkamp algorithm to include gantry tilt is simple and straightforward with no significant increase in computational complexity. The effect of gantry tilt for helical Feldkamp reconstruction is to introduce a lateral shift in the isocenter of the reconstructed slice of interest, which is a function of the tilt, couch speed, and view angle. The lateral shift is easily calculated and incorporated into the helical Feldkamp backprojection algorithm. A tilt-generalized helical Feldkamp algorithm has been developed and incorporated into Aquilion 16-slice CT (Toshiba, Japan) scanners. This paper describes modifications necessary for the tilt generalization and its verification.     

Foreign body in the maxillary sinus--possible plastic tube: a case report

We experienced the case of a patient who had a foreign body in the maxillary sinus. The patient complained of recurrent unilateral badly smelling rhinorrhea. The computed tomography and the magnetic resonance images revealed a foreign body in the maxillary sinus. The foreign body was removed via the Caldwell-Luc approach. The foreign body was a plastic tube, which was supposed to be designed for the drainage of the maxillary sinus. However, the patient did not remember having been subjected to a treatment using such kind of tube. After the surgical removal, the patient became free from the nasal symptoms.     

A case of remission of metastatic gastric cancer lesions in the chest and abdominal wall by 5'-DFUR administration

52-year-old female was weakened and bed-ridden by metastasis of gastric cancer to the chest and abdominal wall, and peritonitis carcinomatosa 2 years after gastrectomy. One week after administration of 5'-DFUR, 1200 mg/d, p.o., a clinical effect was seen. In 3 weeks metastatic lesions had diminished in size, ascites had decreased and the patient had regained her appetite and put on weight. She recovered sufficiently to be able to do some daily work. Pathological degeneration and necrosis of cancer cells were observed. Although she died 8 months after remission, 5'-DFUR was effective in improving her condition and prolonging her life.