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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 847 records · Page 47Linked to original sources

Ocular pigmentation and intraocular pressure response to forskolin.

We studied the effects of a forskolin suspension on intraocular pressure (IOP) in normal albino and pigmented rabbits and in alpha-chymotrypsin induced ocular hypertensive rabbits. Experimental-induced ocular hypertensive rabbits were produced by injecting of alpha-chymotrypsin (167 units) into the posterior chamber of the eye of albino rabbits. Ocular hypertensive rabbits were classified into 3 groups according to the IOP (Group A; 15-19 mmHg, B; 20-24 mmHg, C; 25-29 mmHg). Topical application of 1% forskolin caused a significant decrease in IOP in Groups B and C, as well as in normal albino and pigmented rabbits. The hypotensive effects were lower in pigmented rabbits than in albino rabbits, although the duration was longer. Subconjunctival injection of 1% forskolin reduced IOP 1 to 5 hrs after treatment in albino rabbits. However, in pigmented rabbits, a slight increase in IOP was observed at 30 min, followed by a significant decrease 5 to 10 hrs after injection. Furthermore, the binding ability of forskolin to melanin granules was determined in vitro. Forskolin exhibited specific affinity towards melanin granules obtained from bovine eyes, with the binding reaching a plateau after 5 min of incubation.

Albinism↗

Topographic anatomy and CT correlations in the untreated glioblastoma multiforme.

To provide baseline information for the "local" therapy of the glioblastoma multiforme (GBM), whole-brain histological sections of 15 untreated GBM's were studied to determine the distribution of neoplastic cells. These findings were then compared with the computerized tomography (CT) scans in 11 cases in order to determine the extent to which the peripheral portion of the neoplasm can be estimated by the presence of a low-density area without contrast enhancement. The results of the histological study confirmed the marked heterogeneity of GBM's and disclosed a great variability in the geometry, extent, and character of the peripheral "infiltrating" margin. In spite of the widely held concept that glioblastomas are localized within 2 cm of the contrast-enhanced rim, there were three cases in this two-dimensional study in which this distance was exceeded, and it seems likely that three-dimensional reconstructions would have detected additional cases in which neoplastic cells extended beyond this arbitrary limit. Only three of the 15 GBM's were restricted to the distribution of one internal carotid or one vertebral artery. To the extent that the neoplasms in the present series are representative, this suggests that glioblastomas will be difficult to treat successfully by intra-arterial therapy using existing therapeutic agents. Correlations of histological sections with the CT scans revealed that the vast majority of the neoplastic tissue was contained within the contrast-enhancing and "peritumoral" areas of low density, but that in five cases fingers of neoplasm extended for short distances beyond the outer margin of the latter region. This indicates that the distribution of cells of a GBM cannot be inferred from CT images since the "peritumoral" area of low density can over- or underestimate the extent of the lesion.

Aged↗

A new immunomodulator, FR-900490.

FR-900490 is a new type of immunoactive substance produced by a fungus Discosia sp. F-11809. The colony forming units in culture (cfu-c) in bone marrow cells, which were suppressed by immunosuppressive factor obtained from the serum of sarcoma 180 tumor bearing mouse, was restored to normal level by the addition of FR-900490 in vitro. Furthermore, in mitomycin C (MMC)-treated mice the subsequent administration of FR-900490 caused a significant increase of cfu-c in bone marrow cells depressed by MMC.

Adjuvants, Immunologic↗

A new immunomodulator, FR-900483.

FR-900483 is a new immunoactive substance produced by a fungus, Nectria lucida F-4490. Concanavalin A-stimulated lymphocyte proliferation, which had been suppressed by addition of immunosuppressive factor, was restored to a normal level by the addition of FR-900483. Furthermore, FR-900483 restored the capacity of immunosuppressed mice to produce antibody against sheep red blood cells.

Adjuvants, Immunologic↗

[Anticancer effect of UFT in intrahepatic recurrence with tumor embolus in the left portal vein after hepatectomy of hepatoma--a case report].

A 65-year-old man was diagnosed as having hepatoma (HCC) in the area of S5 and S8. Anterior segmentectomy was performed on September, 1984. TAE (Sandwich therapy) via r. hepatic artery was performed for the intrahepatic recurrence one and half years after hepatectomy. However, the tumor embolus in the l. portal vein with intrahepatic recurrence occurred, and intraarterial infusion chemotherapy (IAC) using CDDP 150 mg was performed via proper hepatic artery. The decrement of AFP value was observed for a short time after IAC therapy. Therefore, UFT 300 mg daily, was administered. For two and half months after UFT administration, the elevation of AFP value continued from 665 ng/ml to 4150 ng/ml, and decreased rapidly below 20 ng/ml in the following 2 months. The tumor embolus in the l. portal vein was remarkably reduced on computed tomogram examination. This case suggests the usefulness of UFT for the intrahepatic recurrence with tumor embolus in the portal vein after hepatectomy for HCC.

Aged↗

[Transarterial chemoembolization in metastatic liver tumor after curative resection of pancreatic cancer].

Transarterial chemoembolization was done for 6 cases with metastatic liver tumor after curative resection of pancreatic cancer. Three cases underwent pancreatoduodenectomy and another 3 caudal pancreatectomy. Anticancer effect, which was determined from the survival period and the changes in tumor size and tumor markers (CEA and NSE), was remarkable in a case of adenosquamous carcinoma and one of islet cell carcinoma. However, in another 4 cases with adenocarcinoma, it was not sufficient. With regard to the adverse effect, liver abscess was seen in two cases after pancreatoduodenectomy. Laboratory data before TACE showed that both of these 4 cases had cholangitis. This is in contrast to the fact 2 of the 3 caudal pancreatectomies had cholangitis, too. Therefore, it is concluded that careful selection is necessary, especially for the case after pancreatic head resection.

Adenocarcinoma↗

[Transcatheter arterial chemoembolization in liver metastases of colorectal cancer (lipiodol cisplatin sandwich therapy].

The transcatheter arterial chemoembolization (LPD-CDDP Sandwich Therapy) developed by us was applied to 15 patients with unresectable liver metastases (H2-H3) of colorectal cancer. Computed tomography or ultra-sonography revealed an overall response rate of 27%. Serum CEA values decreased to lower than the pre-TACE value in 11 (78%) of 14 patients excluding one showing the normal range before TACE. The post-TACE CEA values were completely normalized in 2 of the 11 patients. One-year cumulative survival rate was 72% and median survival was 18 months, showing a prolongation compared with intraarterial or systemic chemo-immunotherapy. The histological antitumor effect of LPD-CDDP Sandwich Therapy was examined in the hepatic specimens from 6 patients who underwent hepatectomy after this therapy for liver metastases (H1-H2) of colo-rectal cancer. The necrotic area in the main tumor was 95-100% in 3 patients, 75-94% in 2 patients and 50-74% in one patient. LPD-CDDP sandwich therapy was considered an effective treatment without any serious side effects for liver metastases of colo-rectal cancer.

Cisplatin↗

[Effectiveness of preoperative transcatheter arterial embolization for improved survival rates in patients with hepatocellular carcinomas (sandwich therapy using ethiodized oil, cisplatin and gelatin sponge].

The effect of hepatic transcatheter arterial embolization (TAE) therapy was evaluated in 153 patients with hepatocellular carcinomas who underwent radical hepatectomy. They were divided into 3 groups. Group A (n = 56) received preoperative TAE using ethiodized oil, cisplatin and gelatin sponge (sandwich therapy). Group B (n = 29) received preoperative TAE using adriamycin + gelatin sponge, ethiodized oil + adriamycin + gelatin sponge or adriamycin + degradable starch microsphere. Group C (n = 68) did not receive TAE preoperatively. The 3-year disease-free survival rates in Group A, B, and C were 56%, 34% and 32%, respectively. The rate was significantly higher in Group A than Group C (p less than 0.05). The 1-year disease-free survival rates after partial hepatectomy were 89% in Group A (n = 22), 53% in Group B (n = 15) and 67% in Group C (n = 22). The 3-year survival rate of these patients in Group A was significantly higher (95%), compared to Group C (70%) (p less than 0.05). Preoperative TAE using ethiodized oil, cisplatin and gelatin sponge (sandwich therapy) was considered a useful therapy for improvement of disease-free survival rates or survival rates after hepatectomy in patients with hepatocellular carcinomas.

Aged↗

[Cell kinetics of human meningiomas and neurinomas--Ki-67 PAP stain].

Seventeen surgically resected meningiomas and six neurinomas including one neurofibroma were labelled with frozen sections using a monoclonal antibody Ki-67, which reacts with a nuclear antigen expressed by proliferating cells. In thirteen classic non-malignant meningiomas, the percentage of stained cells ranged from 0.2 to 3.2% (mean, 1.4%). Those of three recurrencies consisted of anaplastic one and another one with anaplastic component, and one hemangiopericytic type ranged from 2.9 to 8.7% (mean, 4.8%). Four classic non-malignant neurinomas and one neurofibroma had the range from 0.3 to 2.7% (mean, 1.3%). However, one anaplastic neurinoma showed the largest fraction (13.0%) of positive nuclei in all these tumors. These results show, in conclusion, that the determination of Ki-67 immunoreactivity in the cell nuclei of meningiomas and neurinomas can contribute to more objectiveness in histological grading and the higher positive rate could be one of various factors relating to recurrence.

Adult↗

[Cell kinetics of oligodendroglioma and oligo-astrocytoma--Ki-67 PaP study].

In order to determine the principal histologic features in distinguishing the "anaplastic" from the "well differentiated" oligodendroglioma and mixed glioma (oligo-astrocytoma), correlations between the growth fraction, and histologic grade and 6 histologic variables (vascular proliferation, cytologic pleomorphism, calcification, necrosis, cellularity, mitotic index) were studied in 24 patients. The growth fraction was calculated as the percentage of Ki-67-immunostained nuclei in frozen sections using Ki-67 monoclonal antibody. 6 histologic variables were checked with HE stain of paraffin-embedded tissue sections. The growth fraction was in general agreement with the histologic grade, in order of decreasing mean percentage, ranging from 11.1% (anaplastic mixed glioma) to 5.3% (anaplastic oligodendroglioma), 2.8% (isomorphic oligo.) and 1.9% (mixed, grade II). There was a significant association between the growth fraction and 3 histologic variables (vascular proliferation, cytologic pleomorphism, mitotic index) out of 6. Thus, even though there exist some gaps between these parameters in paraffin-embedded tissues and those in frozen sections, the percentage of Ki-67-immunostained nuclei is likely to be very valuable as a supplement information of histological grading and a prognostic indicator.

Adult↗

Glutathione depletion by 2-nitroimidazole-1-acetohydroxamic acid as a radiosensitizer in hypoxic rat hepatocytes.

The effects of nitroimidazoles as radiosensitizers on intracellular glutathione (GSH) level were investigated in rat isolated hepatocytes. Dinitroimidazoles have lowered almost completely GSH level during the incubation for 30 min under oxic (95% O2+5% CO2) condition, while mononitroimidazoles had scarcely affected. In the case of hypoxic (95% N2+5% CO2) condition, however, 2-nitroimidazoles, not 4-nitroimidazoles, as well as 2,4- and 4,5-dinitroimidazoles have caused the significant depletion of GSH. This suggests that nitro group in the 2-position of imidazoles may be responsible for the GSH depletion under hypoxia. Especially, 2-nitroimidazole-1-acetohydroxamic acid (KIH-801) was found to be the most potent GSH depletor only under hypoxic, not oxic conditions, and might be useful for the new hypoxic cell radiosensitizer instead of misonidazole.

Animals↗

Purification, characterization and amino-acid sequencing of two pancreatic secretory trypsin inhibitors in rat pancreatic juice.

We purified two pancreatic secretory trypsin inhibitors (PSTI-I and PSTI-II) from rat pancreatic juice. PSTI-I consisted of 61 and PSTI-II of 56 amino-acid residues. Their amino-acid sequences were similar (40 out of 56 amino acid residues of PSTI-II being identical with those of PSTI-I), but PSTI-I and PSTI-II appeared to be translation products of different genes. There was no difference in inhibitory properties between PSTI-I and PSTI-II.

Amino Acid Sequence↗