Search PubMed⌕ Search

Biomedical subjects

R Yamaguchi

Publications and source records attributed to R Yamaguchi.

250 records · Page 14Linked to original sources

Three dimensional imaging of tracheobronchial system using spiral CT.

The purpose of this study was to evaluate the clinical efficacy of 3D reconstruction of the tracheobronchial system using spiral CT. A total of 25 patients with tracheobronchial abnormalities, stenosis (n = 21) and fistula with esophagus (n = 4), underwent a single breathhold spiral CT (5 mm collision, 5 mm)/s increment). With respect to localization, extent and degree of stenosis and size of fistula were compared with findings at bronchoscopy. The CT location and extent of stenoses were consistent with bronchoscopic findings in all 21 patients. The diameter and shape of the lesions were not evaluated in five patients with severe stenoses. In patients with fistula, 3D CT image demonstrates the location and size of fistula in all four patients. Spiral CT serves to demonstrate accurate and useful 3D reconstruction images for planning and monitoring therapy.

Adult↗

Expression and localization of vascular endothelial growth factor receptors in human hepatocellular carcinoma and non-HCC tissues.

Flt-1 (VEGF receptor-1) and KDR/Flk-1 (VEGF receptor-2) are the high-affinity receptors for the angiogenesis factor, vascular endothelial growth factor (VEGF). VEGF expression has been confirmed in human hepatocellular carcinoma (HCC), and VEGF is thought to be involved in the angiogenesis within HCC tissues. However, expressions of VEGF receptors in HCC have not been reported. We immunohistochemically examined expressions and localizations of Flt-1 and KDR in 28 surgically resected HCC tissues. In non-cancerous area, Flt-1 and KDR were mainly found in macrophages including Kupffer cells; both receptors were found in vascular endothelial cells in the portal veins and arteries within portal tracts; and KDR was also found in some sinusoidal endothelial cells. In cancerous area, Flt-1 and KDR were found in some macrophages, and also in the endothelial cells of intratumoral blood vessels. In 25 moderately and/or poorly differentiated HCCs, KDR expression in the blood space endothelial cells was clear and continuous in 20 cases, and focal in 5 cases. These results suggest that there would be an angiogenesis mechanism via VEGF/Flt-1 or VEGF/KDR in HCC, and the VEGF/KDR system would take a more important role.

Carcinoma, Hepatocellular↗

Fibrolamellar carcinoma of the liver.

We report a resected case of fibrolamellar carcinoma (FLC) of the liver that occurred in a 21 year-old Japanese male with a normal liver. Lymph node metastases around the common hepatic artery and the hepatic hilum were revealed by a post-operative histological examination. He was in good health 7 months after the surgery. This case demonstrates typical findings of FLC, radiologically and histologically. The details are described in this report. Moreover, after reviewing 12 Japanese cases, we emphasize the differential diagnosis of focal nodular hyperplasia (FNH) as the following: 1) Calcification is frequently seen in FLC. 2) The central scar of FLC is visualized as an area of low intensity on T2-weighted magnetic resonance imaging (MRI).

Adult↗

Activation of progelatinase B in synovial fluids of patients with rheumatoid arthritis, with reference to stromelysin-1 and tissue inhibitor of matrix metalloproteinase-1.

OBJECTIVE: To clarify whether stromelysin-1 and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are involved in the modulation of activation of progelatinase B in the synovial fluid of patients with rheumatoid arthritis (RA). METHODS: Gelatinases in the synovial fluid of patients with RA were analyzed by gelatin zymography. Concentrations of stromelysin-1 and TIMP-1 were measured using a specific sandwich enzyme linked immunosorbent assay. RESULTS: Forty-three rheumatoid synovial fluids containing progelatinase B were examined to clarify whether the enzyme was activated by incubation. Incubation at 37 degrees C caused the conversion of progelatinase B to the active form in 22 of the 43 synovial fluids. The levels of both stromelysin-1 and TIMP-1 were determined for each group and the concentration ratio of stromelysin-1/TIMP-1 in the synovial fluids of each group was highly correlated to the activation of progelatinase B. CONCLUSION: The balance between the concentrations of stromelysin-1 and of TIMP-1 in the synovial fluid appears to determine whether the progelatinase B molecule causes conversion into the active form.

Arthritis, Rheumatoid↗

Importance of Escherichia coli infection in ascites in broiler chickens shown by experimental production.

Common commercial strain male broilers aged 14 days were intratracheally inoculated with 0.2 ml of 1.2 x 10(6) colony-forming units of Escherichia coli in nutrient broth and kept in a cool environment during the experiment. Ascites was produced in five surviving and two dead birds out of 50 but not in 50 mock-infected control birds. Among the 40 survivors that were infected, the erythrocyte packed cell volume (PCV) of the 10 birds with pericarditis was the same as in 21 grossly normal birds, although that of the four birds with enlarged right ventricle (RV) was high. The pericarditis caused by E. coli septicemia was not the primary cause of ascites. However, the PCV was high in some of the survivors with an enlarged RV without pericarditis, indicating overload due to the lung lesion. These data suggested that some of the birds with an enlarged RV, caused by supplying blood that was insufficiently oxygenated for the body size, suffered from ascites.

Animals↗

Experimental production of ascites in broiler chickens using infectious bronchitis virus and Escherichia coli.

Common commercial strain male broilers were intratracheally inoculated with 0.3 ml of fluid containing 10(3.7) embryo infective doses of infectious bronchitis virus (IBV) at 14 days of age and 7.5 x 10(6) colony-forming units of Escherichia coli at 18 days of age. Ascites was detected in 15 out of 100 infected birds, which was significantly higher than in a control group of 100 mock-infected birds (P < 0.01). Some parabronchi were blocked by copious exudate containing heterophils and fibrin in the infected birds at 22 days of age although these findings were not seen in the infected birds at 35 days of age or in birds with ascites. The erythrocyte packed cell volume and right ventricle/total ventricle (RV/TV) ratio of birds with ascites were higher than in birds without ascites. The RV/TV weight ratio for the infected group at the age of 35 days was higher than that of the control group. No IBV or E. coli were recovered from the ascitic birds. These findings suggest that these infectious agents induce ascites in the broilers, and then disappear until the birds suffer from ascites.

Air Sacs↗

Correlation between the appearance of gelatinases in the synovial fluid of patients with rheumatoid arthritis and polymorphonuclear elastase, stromelysin-1, and the tissue inhibitor of metalloproteinase-1.

OBJECTIVE: To clarify whether gelatinases in the synovial fluid are related to rheumatoid arthritis (RA). METHODS: Gelatinases in the synovial fluid of patients with RA were analyzed by gelatin zymography. RESULTS: We classified patients into 3 distinct groups based on the gelatinases present. Although inactive gelatinase A was found in the synovial fluid of all patients with RA, the presence of gelatinase B varied: group I contained none, group II contained inactive gelatinase B, and group III contained active gelatinase B. The presence of gelatinase B was positively correlated with the polymorphonuclear (PMN) elastase content of the synovial fluid. Furthermore, the presence of activated gelatinase B correlated well with the stromelysin-1 content. Conversely, large amounts of the tissue inhibitor of metalloproteinase-1 (TIMP-1) were found in the synovial fluid of patients in group II. CONCLUSION: The appearance and form of gelatinase B may reflect the inflammatory condition of patients with RA.

Arthritis, Rheumatoid↗

The use of feed restriction for mortality control of chickens in broiler farms.

Feed restriction was attempted for the control of mortality at broiler farms. Respiratory signs were observed in both restricted-feed flocks and fully fed flocks, but they were less severe in the restricted-feed flocks. The death rate in the fully fed flocks began to rise at the age of 4 wk but did not do so in the restricted-feed flocks. Mortality in the restricted-feed flocks was significantly lower than in the fully fed flocks aged from 3 to 7 wk. The economic performance with restriction feeding was better than that with full feeding as a result of improvements in viability and feed conversion rates. Feed restriction appeared to be beneficial in decreasing the death losses.

Age Factors↗