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Biomedical subjects

R Matsui

Publications and source records attributed to R Matsui.

At least 73 records · Page 4Linked to original sources

Three-dimensional CT angiography of the splenic-portal venous system by using multiple threshold display.

We assessed the three-dimensional (3D) CT angiographic reconstruction of the splenic-portal venous system obtained by using multiple threshold display (MTD) in 40 patients with liver disease. In each patient, both shaded surface display(SSD) and MTD images were generated by using an Xtension with a Sun SPARCstation 20, and they were compared by two radiologists. MTD image quality was superior to that of SSD images, because MTD diminished longitudinal direction artifacts and the image depicted the small vessels clearly. Based on the above results, we consider MTD to be a useful method for 3D-CT angiography of the splenic-portal venous system.

Angiography↗

Development of a chronic skin defect model and a study of cytokine secretion using the model.

In this study, we established a delayed healing chronic type wound model in order to investigate the etiology of chronic wound healing, including wound contraction. Establishment of the model was important for clarification of the mechanism(s) of chronic wound healing and wound contraction and for use in evaluating therapeutic efficacy. A pedicled skin flap was raised beneath the panniculus carnosus membrane on the backs of mice, and after the loose connective tissue at the base of the flap was completely removed surgically, the flap was replaced and sutured. Seven days after surgery, a full-thickness defect measuring 1.5 x 1.5 cm was made in the center of the skin flap. At that time, a defect of the same size, including the panniculus carnosus membrane, was made in another group of mice as controls, and changes with time in wound area were compared between the two groups. The exudate retained on the wound surface was collected, and various cytokines contained in the exudate were measured. In the control group, the wound rapidly contracted and almost completely epithelialized and closed 21 days after surgery. On the other hand, the wound area was significantly larger in the delayed model than in the control animals during the observation period, revealing a delay in wound contraction. Transforming growth factor-beta, interleukin-1beta, and tumor necrosis factor-alpha in the exudates from the wound of the model were significantly higher than in those of the control group, whereas interleukin-6 was low in the model. From these results, it was concluded that this model could be a useful experimental system for studies on wound contraction as well as clarifying the mechanism of so called chronic type wounds.

Animals↗

Two different patterns of airway branching regulated by different components of the extracellular matrix in vitro.

This study examined the effects of beta-D-xyloside (an inhibitor of proteoglycan synthesis) and cis-4-hydroxyl-L-proline (an inhibitor of collagen synthesis) on branching morphogenesis in cultures of fetal rat lung. Lungs from day 15 gestation were incubated for 4 days in (1) the control medium (Dulbecco's Modified Eagle Medium + 10% Fetal Bovine Serum) alone (control), (2) control medium plus 2 mM beta-D-xyloside (beta-XYL), (3) control medium plus 2 mM alpha-D-xyloside (alpha-XYL), (4) control medium plus 50 micrograms/mL cis-4-hydroxy-L-proline (cis-HYP). The number of peripheral buds of left lungs was counted daily. Histological examination was performed on lungs on days 2 and 4. beta-XYL inhibited proximal monopodial branching on day 2 without affecting lung size, but produced numerous peripheral buds on day 4 which were of abnormal appearance, suggesting that lung airway branching and growth may be regulated by different mechanisms. Histology and morphometry showed significantly enlarged airspaces and diminished mesenchyme. cis-HYP did not affect proximal branching on 2 days in culture, but inhibited further dichotomous branching and lung growth after 2 days. On day 4, diminished branching and lung growth was accompanied by a proportional decrease in mesenchyme. The difference between effects of beta-XYL and cis-HYP on the branching pattern suggests that proteoglycans and collagen are involved in different patterns of branching morphogenesis.

Animals↗

Three-dimensional computed tomographic angiography of pulmonary vessels.

OBJECTIVE: To assess the image quality of multiple threshold display (MTD) as a new technique for generating three-dimensional (3D) pulmonary computed tomographic (CT) angiographic images. METHODS: We used MTD, a type of shaded surface display (SSD) offering the selection of multiple thresholds and transparencies, to reconstruct 3D-CT angiograms from enhanced helical CT data sets in 33 patients with lung disease. In MTD, eight thresholds of CT values are selected, and transparency is assigned to each. The selected voxels, ranging from -600 to 1,000 Hounsfield Units, were divided into eight classes, and transparency ranging from 0 to 100% was assigned to each. The CT scanner employed was a Toshiba Xvigor. MTD and SSD images were generated by using an Xtension with a Sun SPARC station 20, and they were compared by two radiologists. RESULTS: The image quality of MTD images was superior to that of SSD images (p < 0.01), because the MTD images demonstrated clearly both the major and small vessels. CONCLUSION: MTD is a useful technique for 3D pulmonary CT angiography.

Female↗

External radiotherapy for decompression of cholangiocellular carcinoma with obstructive jaundice: report of a case.

Percutaneous transhepatic catheter drainage (PTCD) is generally performed for the treatment of obstructive jaundice. However, in some cases it is difficult to perform insertion because of lack of dilatation of the intrahepatic bile duct. We report a patient who had been suffering from jaundice as a result of recurrent cholangiocarcinoma near the hilum and whose symptoms were relieved by external radiotherapy. We consider radiotherapy for cholangiocarcinoma effective palliative treatment for decompression of obstructive jaundice.

Bile Duct Neoplasms↗