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Biomedical subjects

T Tamada

Publications and source records attributed to T Tamada.

At least 73 records · Page 4Linked to original sources
PubMed1993

Crystallization and preliminary X-ray diffraction studies of photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans.

Photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans was crystallized by the hanging drop vapor diffusion procedure using ammonium sulfate as a precipitant. The pale-yellow crystals were grown to a size of 0.4 mm in length and 0.1 mm in diameter. They belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 with unit cell dimensions of a = b = 90.7 A and c = 135 A. Assuming that the asymmetric unit contains one molecule, the Vm value is calculated as 2.6 A3/dalton. The crystals are stable towards X-ray exposure and diffract beyond 2.5 A resolution.

Crystallization↗
PubMed1993

Fibrinolytic components in fetal membranes and amniotic fluid.

OBJECTIVE: We evaluated fibrinolytic components in plasma and amniotic fluid of pregnant women and in postpartum fetal membranes. STUDY DESIGN: Fibrinolytic parameters in amniotic fluid and plasma were measured by means of enzyme-linked immunosorbent assays. Fetal membranes collected after spontaneous labor at term were analyzed by immunohistochemical methods with immunospecific antibodies against fibrinolytic components. RESULTS: Amniotic fluid contained high plasminogen activator inhibitor-1 concentrations but had low activity. Strong staining for plasminogen activator inhibitor-1 and vitronectin was observed in chorionic trophoblasts and moderate staining in decidual connective tissue. Strong staining for plasminogen activator inhibitor-2 was seen in decidual cells. Although prominent staining of plasminogen activators and plasminogen were observed in the amniotic epithelium, virtually no plasminogen activator inhibitor-1, plasminogen activator inhibitor-2, or alpha 2-plasmin inhibitor staining was detected. CONCLUSION: The delicate balance of fibrinolytic activators and inhibitors in fetal membranes and amniotic fluid may contribute to the triggering of membrane rupture at term.

Amniotic Fluid↗
PubMed1993

Studies on the permeability and enzyme-cytochemistry of the mouse hemotrichorial placenta.

The permeability of higher molecular weight substances was investigated in mouse chorioallantoic labyrinthine hemotrichorial placenta, using horseradish peroxidase as a tracer. At the same time, ultrastructural localizations of some important enzymes, such as alkaline phosphatase (ALP), acid phosphatase (ACP), Ca(++)-ATPase and guanylate cyclase were elucidated in this organ by means of the enzyme-cytochemical technique. Peroxidase easily entered the space between layers I and II, and no penetration of this tracer beyond layer II was observed. The reaction products for ALP activity were found mainly on the maternal side of the plasma membrane of the layer II trophoblast. ACP activity was confined to the lysosomes of this layer II cell. In short, peroxidase stopped at the cell surface of the layer II trophoblast, and both ALP and ACP coexisted in this layer II cell. These observations strongly suggest that the layer II trophoblast, especially the surface plasma membrane of this cell, may have an important role in regulating the materno-fetal transfer of substances in mouse chorioallantoic placenta.

Acid Phosphatase↗
PubMed1993

Increased levels of plasma thrombomodulin in preeclampsia.

Plasma levels of thrombomodulin (TM), a glycoprotein found on the surface of the endothelial cells, are elevated in certain diseases that are characterized by damage to the vascular endothelium. Such damage is thought to be involved in preeclampsia. We therefore studied the plasma levels of this substance in 13 preeclamptic women as compared with 14 normal pregnant and 16 nonpregnant women. We found that the plasma levels of TM were significantly elevated in preeclamptic women vs. controls. A significant positive correlation was observed between the plasma TM level and that of serum creatinine. It is thus suggested that elevated TM levels in preeclampsia may reflect a decrease in renal clearance rather than vascular endothelial damage.

Adult↗
PubMed1993

Macrophage colony-stimulating factor as a tumor marker for epithelial ovarian cancer.

OBJECTIVE: To determine the serum level of macrophage colony-stimulating factor in ovarian cancer patients in order to evaluate its role as a marker for ovarian cancer. METHODS: Serum macrophage colony-stimulating factor levels were assayed in 69 patients with epithelial ovarian cancer, 55 with benign ovarian tumors, and 634 healthy individuals, including 398 women, using an enzyme-linked immunosorbent assay. RESULTS: The average serum macrophage colony-stimulating factor level was 754.4 +/- 153.9 U/mL in healthy females; 1056 U/mL (mean plus 1.96 standard deviations) was considered to be the upper limit of normal. Serum macrophage colony-stimulating factor levels were significantly elevated in patients with ovarian cancer (average 1460.5 +/- 1006.2 U/mL; P < .001) and exceeded 1056 U/mL in 42 of the 69 patients with ovarian cancer (61%). No differences in levels were observed among the histologic types. No definite relationship was found between serum levels of macrophage colony-stimulating factor and those of CA 125. We found that 96% of the patients with ovarian cancer had high serum levels of macrophage colony-stimulating factor and/or CA 125 values. There was no significant difference in the levels of macrophage colony-stimulating factor between patients with benign ovarian tumors and healthy controls. Only 7.3% of the group with benign tumors had levels exceeding 1056 U/mL. CONCLUSION: Macrophage colony-stimulating factor is a marker for ovarian cancer. Determination of serum levels can be useful in detecting ovarian cancer, particularly in combination with CA 125.

Adult↗
PubMed1992

In vivo measurement of spatial dose distribution with thermoluminescent sheet around high dose-rate intracavitary source: application to rectal cancer.

For intracavitary high dose-rate radiation therapy, a thermoluminescent [TL] sheet for in vivo measurement of spatial dose distribution around source has been recently developed. The TL sheet was found to have a linear response with a very wide dynamic range from at least 0.002 cGy to 5000 cGy for 60Co gamma-rays. This TL sheet (40 cm x 50 cm x 200 microns), which is composed of Teflon mixed with BaSO4:Eu doped powder, is very flexible and can be cut to the desired size. In addition, this sheet is easy to handle because of its insensitivity to room light. The spatial dose distribution is displayed in a color mode by using a newly developed TL sheet readout system. For a clinical application, the TL sheet was wrapped on an applicator for intracavitary radiation therapy of a rectal cancer and was inserted into the rectum. The location of the TL sheet could be confirmed with diagnostic X ray film. After irradiation with high dose-rate 60Co source, the in vivo relative dose distribution on the surface of the rectum was determined. This TL sheet provided a convenient means of measuring the relative dose distributions around 60Co sources of various patterns in intracavitary radiation therapy.

Brachytherapy↗
PubMed1992

Thymidylate synthase activity in normal and malignant gynecologic tissues.

We assayed thymidylate synthase (TS) activity in normal and malignant gynecologic tissues. TS activity in the normal cervix, secretory endometrium, and ovaries from a total of 61 patients was 1.00 +/- 0.52 pmol/g tissue (mean +/- SD). Thus the upper limit (mean + 2SD) of TS activity in normal gynecologic tissue was 2.00 pmol/g tissue. TS activity was generally higher in malignant tissue than in normal tissue, and particularly high activity was detected in cervical cancer. TS activity in endometrial cancer was relatively low, but activity in poorly and moderately differentiated tumors was significantly elevated compared to well differentiated tumors. These findings suggest that cervical cancer is a highly proliferative tumor and that in endometrial cancer, cell proliferation is more rapid in poorly differentiated tumors than in well differentiated ones.

Endometrial Neoplasms↗
PubMed1992

[A study on the proliferation of the uterine endometrium].

UNLABELLED: A proliferative activity study of the endometrium was evaluated in three different parts by means of an immunohistochemical approach and flow cytometry (FCM). The materials were 29 cases of hysterectomies due to uterine myoma. Twenty-one cases were in the proliferative phase, and 8 cases were in the secretory phase. The three parts of the endometrium obtained from the upper, middle and lower part of the uterine body were investigated by an immunohistochemical technique with Ki-67 and anti-DNA polymerase alpha antibody. Single staining with Propidium Iodide (PI) was used for cell cycle analysis in FCM. RESULTS: (1) The rate of positive Ki-67 cells was 25.9 +/- 6.3% in the upper part, 26.0 +/- 3.3% in the middle part, and 25.5 +/- 5.8% in the lower part. And the rate of positive DNA polymerase alpha cell was 27.2 +/- 5.8% in the upper part, 24.0 +/- 2.9% in the middle part, and 24.8 +/- 4.0% in the lower part. The growth potential of each part was not significant. (2) FCM did not detect a significant difference among the three parts of the endometrium in cell cycle analysis. (3) Hematoxylin-eosin staining showed that the upper part was thicker than the lower part and the number of glands in the upper part was more abundant than in the lower part. This difference was significant (p less than 0.01). (4) Ki-67 was recognized even in the early secretory phase. (5) And each segment of the endometrium proliferated evenly, not focussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1991

Anticancer activity of the combination of cisplatin and etoposide in endometrial cancer-bearing nude mice.

We investigated the efficacy of the combination of cisplatin and etoposide in endometrial cancer using mice bearing human endometrial cancer. Cisplatin (5 mg/kg) plus etoposide (10 mg/kg) caused markedly greater inhibition of the growth of medium-sized tumors (96.1% inhibition) than cisplatin alone at the same dose. Similarly, the combination of cisplatin (7.5 mg/kg) and etoposide (10 mg/kg) produced a significantly higher complete remission rate in small tumors, compared with cisplatin alone at the same dose (82.6% vs 35.3%, P less than 0.01). As a single agent, etoposide had almost no inhibitory effect on tumor growth and produced a considerably lower complete remission rate. Total platinum and etoposide concentrations in serum and tumor tissue were unaltered when these agents were used either singly or in combination. Our results suggested that combination cisplatin-etoposide therapy was synergistic against endometrial cancer.

Animals↗
PubMed1991

Evidence that the 75K readthrough protein of beet necrotic yellow vein virus RNA-2 is essential for transmission by the fungus Polymyxa betae.

Two mutant strains of beet necrotic yellow vein virus (BNYVV) containing deletion mutants of RNA-2 were produced during serial passage in mechanically inoculated Tetragonia expansa leaves. The mutant strains were referred to as S-0a (RNA-1 + 2a) and G-0b (RNA-1 + 2b). RNA-2a and RNA-2b were about 4.3 kb and 4.2 kb in length, respectively, whereas normal sized RNA-2 was about 4.8 kb in length. In vitro translation and immunoblot analysis showed that RNA-2, RNA-2a and RNA-2b all directed synthesis of the coat protein (Mr 22K). However, whereas wild-type RNA-2 also directed the synthesis of a coat protein readthrough protein with an Mr of 83K (predicted Mr 75K), RNA-2a and RNA-2b directed the production of readthrough proteins with MrS of 67K and 58K, respectively. This suggests that the deleted regions of RNA-2a and RNA-2b occur within the second open reading frame, which encodes a polypeptide of Mr 54K, which is translated by readthrough of the coat protein cistron. After the addition of wild-type RNA-3 and RNA-4 to all the strains, the mutant strains could not be transmitted by Polymyxa betae zoospores produced from either zoosporangia or resting spores, whereas the wild-type strains were readily transmitted. These results indicate that the 75K readthrough protein encoded by RNA-2 is essential for the transmission of BNYVV by P. betae.

Blotting, Northern↗
PubMed1991

Protective effect of elastase on cis-platinum-induced renal toxicity.

The protective effects of elastase (Ela) and fosfomycin against renal toxicity of cis-diamminedichloroplatinum (II) (CDDP) were evaluated in an experimental study using rats. When Ela was used concomitantly with CDDP, the elevation of urinary N-acetyl-beta-D-glucosaminidase levels in the early phase and the sharp fall in these levels in the latter phase were prevented. It was also found that the blood urea nitrogen levels and serum creatinine levels were significantly lowered. Histologically, atrophic and necrotic changes in the tubular epithelium were prevented. The total serum platinum levels showed no change with the addition of Ela; however, the platinum levels in the renal tissues were significantly reduced. These results suggested that Ela is effective against platinum deposits in the renal tissues, particularly in the tubular epithelium, thus protecting the kidneys. On the other hand, fosfomycin demonstrated no such positive results suggestive of a protective effect on the renal function parameters or during histological observation.

Acetylglucosaminidase↗
PubMed1991

[Establishment and characterization of a human undifferentiated carcinoma cell line (HMG)].

The undifferentiated carcinoma cell line (HMG) was established from a nude mouse tumor which had been produced by transplantation of a intraperitoneal tumor of 27-year-old woman. The HMG cell line has the following biological properties. 1. The HMG cells are round to oval in shape and grow as floating cell aggregates like a rouleau or a cluster of grapes. 2. 100 passages have been carried out over a year, and the population doubling time is about 17 hrs. 3. In the original tumor, keratin and vimentin were expressed simultaneously, in HMG cells, however, only localization of vimentin was confirmed. 4. By chromosomal analysis, over 90% of the cells revealed 46, XX, with no karyological abnormalities, at passage 82. 5. When heterotransplanted into the subcutis of a nude mouse, HMG cells produced a undifferentiated carcinoma resembling the original tumor.

Adult↗
PubMed1991

[Changes in coagulability and fibrinolytic activity in the patients with ovarian hyperstimulation syndrome].

Ovarian hyperstimulation syndrome (OHSS) is occasionally seen following hMG-hCG treatment in combination with a GnRH agonist. Increased coagulability and decreased renal perfusion may be life threatening in some severe cases. In order to evaluate coagulo-fibrinolytic activity, several related factors in the general circulation were examined for approximately 2 weeks after admission in 11 patients with severe OHSS. The results are as follows. 1. Fibrinopeptide A (FPA) was increased during the initial stage of OHSS followed by a gradual decrease. However, the level remained slightly higher than normal for 2 weeks after the onset of severe OHSS. 2. Fibrinopeptide B beta 15-42 (FPB beta 15-42) showed grossly similar patterns to those of FPA. 3. D-dimer levels were constantly higher than normal from the initial to the late stages of OHSS. 4. Thrombin-Antithrombin III complex (TAT) was markedly increased on the days of admission followed by a gradual decrease during the following week. 5. Antithrombin III (ATIII), plasminogen and alpha 2 plasmin inhibitor (alpha 2PI) showed only minimal decreasing patterns throughout blood samplings. 6. Increases in FPA, FPB beta 15-42 and D-dimer were greater in the cases with severe hemoconcentrations. Our present data suggest that severe OHSS brings on hypercoagulability resulting in microthrombosis. In order to avoid development of coagulopathy, prophylactic treatment should be considered for patients with OHSS.

Adult↗