Biomedical subjects
Publications and source records attributed to J Yoshida.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 66-year-old Japanese woman whose cystic duct drained into an aberrant bile duct was found to have an intersegmental connection bridging the right anterior and posterior ducts. The patient had cholelithiasis but no history of hepatic trauma, lending support to congenital etiology for the intersegmental duct. In the presence of aberrant bile ducts, a meticulous search may reveal such biliary communications.
We reviewed computed tomography (CT) in eight patients with sclerosing hepatocellular carcinoma who underwent resection. Dynamic CT was performed 25-40 s (rapid phase) and 5-10 min (late phase) after injection of contrast medium. Most of the lesions were round and homogeneous. Tumors tended to show density equal to the liver. The relative density of the tumors in the rapid phase, however, tended to be higher than in other phases. A peripheral low-density area was absent. Dynamic CT was thus important in the diagnosis of sclerosing hepatocellular carcinoma.
OBJECTIVE: To analyze CT findings of Bellini duct carcinoma, a rare variant of renal cell carcinoma. MATERIALS AND METHODS: The CT findings of five cases of Bellini duct carcinoma were reviewed and the findings were recorded. RESULTS: In all cases the affected kidneys maintained the normal outer contours. In four cases the renal masses protruded into the central sinuses. Contrast enhancement was minimal in four cases. CONCLUSION: Bellini duct carcinoma should be suspected in cases with these CT findings.
A 69-year-old woman with a 15-year history of abnormal chest shadow was referred to our hospital. An enhanced chest CT scan of the anterior mediastinum revealed a mass containing a high-density area. The preoperative radiologic diagnosis was thymoma. Operation was performed in October 2000. Histologically, multiple ossified areas were observed within the tumor. Intratumoral ossification has never been reported in thymoma. Therefore, we report the first case of thymoma associated with multiple foci of osseous metaplasia.
A 57 year old Japanese male was incidentally found to have a 7.5 cm diameter hepatic haemangioma. Eleven years later he was operated on because the haemangioma had grown into a 17 cm mass causing upper abdominal fullness. Volumetry on computerized tomograms disclosed that the haemangioma had grown from 123 cm3 to 1343 cm3 in volume. Quantitative documentation on growing hepatic haemangioma has been rare.
75 year old female who was hospitalized for abdominal pain and fever up on 12th May 1998. She had been followed as a polycystic kidney patient since few years. The swelling of the right kidney and her general condition became gradually worse. On 18th May, the embolization to the right kidney using pure alcohol and gelatin sponge was performed. Within a month, CT scan showed the reduced volume of the right kidney and her blood examination data as well as her general condition became gradually well. And on 17th June, she left our hospital without any complication.
An acidic glycoprotein (SAGP) purified from an extract of Streptococcus pyogenes has been shown to inhibit the growth of methylcholanthrene-induced fibrosarcoma A (Meth A) cells via pertussis toxin-sensitive GTP-binding protein. The present study revealed that SAGP has activity to induce apoptosis in Meth A cells as assessed by DNA fragmentation and cell morphology with chromatin staining. The SAGP-induced DNA fragmentation in Meth A cells was augmented by herbimycin A, an inhibitor of protein tyrosine kinase, and prevented by orthovanadate, an inhibitor of protein tyrosine phosphatase. The growth inhibitory effect of SAGP on Meth A cells was reduced by orthovanadate, whereas the effect tended to be increased by herbimycin A. Western blotting analysis using antiphosphotyrosine antibody demonstrated that tyrosine phosphorylation of 170 kDa cellular protein was diminished in the cells incubated with SAGP. The inhibition of protein tyrosine phosphorylation was neither observed in the cells incubated with SAGP and orthovanadate nor in the cells incubated with heat-inactivated SAGP. These findings indicate that inhibition of tyrosine phosphorylation by protein tyrosine phosphatase(s) may be responsible for the SAGP-induced apoptosis and inhibition of cell growth.
The caudate efferent fibers to the globus pallidus are inhibitory in nature. The pallidothalamic fibers are also inhibitory, exerting monosynaptic IPSPs on the thalamic cells located anteroventrally to the ventrolateral nucleus. Therefore, these two inhibitory neuronal circuits make a double inhibitory chain. To operate the inhibitory circuit, excitatory input to the pallidum is necessary. Stimulation of the ipsilateral brain stem including lemniscus medialis, mesencephalic reticular formation and some other structures, produces short latency excitation of the pallidal cells.
PURPOSE: To evaluate the utility of adriamycin in radiation therapy for hypopharyngeal cancer. PATIENTS AND METHODS: Forty-five patients with hypopharyngeal carcinoma without distant metastasis were treated. Adriamycin was administered i.v. and weekly (15 mg i.v./once a week, median 64 mg) concurrently with radiation therapy to 38 patients, 76% (34 out of 45) of whom were in an advanced stage (III or IV). RESULTS: Overall survival, cause specific survival and local control rates at 5 years were respectively, 49%, 66% and 69% and better than results obtained in the 1970's. Radiation therapy achieved an 84% (38 out of 45) response rate at 40 Gy. Treatment without voice function loss was attained for 16 patients, consisting of 15 local CR (all T1 and 12 out of 26 T2 tumors) by radical radiation therapy and one posterior wall resection for a T2 tumor. Overall and cause specific survival rates were 57% and 91% at 5 years. Twenty patients who underwent further surgery showed 69% overall and 74% cause specific survival rates. The remaining nine patients, who lost local control, died within 16 months. In 18 patients with T2 cancer originating from the pyriform sinus, 69% local control was obtained for patients using adriamycin compared with 20% for patients without adriamycin (p = 0.17). No severe side effect from the addition of adriamycin has been found so far. CONCLUSIONS: Radiation therapy using low dose adriamycin with or without follow-up surgery is safe and has potential to be a good option.
Neurofibromatosis type 2 (NF2) is a formidable disease with considerable morbidity. Among tumors associated with NF2, schwannomas are the most difficult to treat because they are multiple and tend to recur. Vascular endothelial growth factor (VEGF) has been reported to act as a survival factor for Schwann cells. We, therefore, investigated VEGF expression in NF2-associated and sporadic schwannomas. We also evaluated the proliferative potential of these tumors by Ki-67 staining (MIB-1 labeling index) and microvascular density by CD34 staining. Immunohistochemistry was performed in 8 schwannomas from 6 NF2 patients, 2 schwannomas from 2 probable NF2 patients and 10 sporadic schwannomas. VEGF immunostaining was present in most schwannomas: all sporadic schwannomas and 8 of 10 schwannomas from NF2 or probable NF2 patients (NF2 group). No difference was evident in VEGF staining between the 2 groups. MIB-1 labeling index was significantly higher in the NF2 group (3.8 +/- 1.7) than the sporadic group (2.0 +/- 1.0, p < 0.01). Microvascular density was higher in the NF2 group (12.9 +/- 6.0) than the sporadic group (9.4 +/- 3.5), but not significantly (p = 0.06). Although VEGF alone cannot explain the higher proliferative potential in NF2-associated schwannomas, VEGF could be a factor influencing the proliferative potential of schwannomas.
As part of the 5th collaborative study of the Collaborative Study Group for the Micronucleus Test (CSGMT), the sensitivity and advantages of the micronucleus assay using mouse peripheral blood cells were evaluated using 5-fluorouracil (5-FU) and 6-mercaptopurine (6-MP). The peripheral blood cells were collected from a tail vein of CD-1 male mice just before and 24-120 h after intraperitoneal injection. At 24-h intervals. The maximum incidence of micronucleated reticulocytes (MNRETs) at 50 mg/kg 5-FU was observed 96 h after injection; at 100 mg/kg, the peak was delayed to 120 h, and followed severe bone marrow depression. With 6-MP, maximum MNRETs were observed 48 h after treatment at all doses tested. At dose levels higher than 50 mg/kg, severe bone marrow depression was observed after maximum MNRETs. Though the appearance patterns of MNRETs and the bone marrow depression were different between 5-FU and 6-MP, the positive response of both chemical could be detected with this assay system as well as with the micronucleus test using femoral bone marrow cells.
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An acidic glycoprotein (SAGP), purified from crude extract (CE) of Streptococcus pyogenes, inhibits the growth of murine fibrosarcoma (Meth A) cells in vitro and prolongs the life span of mice inoculated with the same cells. This study revealed that the growth inhibitory activity of SAGP on Meth A cells in vitro was lowered in the presence of sulfhydryl-oxidizing agents such as cystamine and 5, 5'-dithiobis (2-nitrobenzoic acid) in a dose dependent manner. The activity of SAGP was also diminished by pretreatment of SAGP with cystamine. Inactivation of SAGP by cystamine was reversed by dithiothreitol. Furthermore, the effect of CE on prolonging the life span of Meth A-bearing mice was reduced by the administration of cystamine. These findings suggest that SH-groups are involved in the expression of anti-tumor activity of SAGP or CE in vitro and in vivo.
In hepatic digital subtraction angiography, artifacts caused by diaphragmatic motion can interfere with the correct diagnosis of hepatic lesions. This article describes the feasibility of using the exhalation holding method in reducing diaphragmatic motion artifacts in hepatic DSA. The authors compared respiratory holding methods in 30 patients who underwent hepatic DSA. They performed a blind comparison of images to assess diaphragmatic motion artifacts. Results showed the images obtained by the exhalation holding method were superior to those obtained by the inhalation holding method in 20 out of 30 series (66.7%).