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Biomedical subjects

M Sugimura

Publications and source records attributed to M Sugimura.

At least 109 records · Page 6Linked to original sources
PubMed1993

Saturation of tumour cell surface receptors for urokinase-type plasminogen activator by amino-terminal fragment and subsequent effect on reconstituted basement membranes invasion.

Single-chain urokinase-type plasminogen activator (pro-uPA) is bound to a specific surface receptor on ovarian cancer HOC-I cells that is incompletely saturated. Saturation of uncovered receptors by uPA polypeptides with intact amino-terminal fragment (ATF) derived from pro-uPA by limited proteolysis (human leucocyte elastase [HLE] or V8 protease) has been studied. HOC-I cells preferentially invaded reconstituted basement membranes in a time- and plasminogen-dependent manner. This process was inhibitable by preincubation with uPA polypeptides in the medium at levels which suggested that complete saturation of cell surface uPA receptors occurred. This result indicates that occupation of uPA receptors by enzymatically inactive uPA fragments or prevention of rebinding of pro-uPA synthesised by tumour cells to the receptors specifically reduces the invasion of the tumour cells through basement membranes in vitro.

Cell Movement↗
PubMed1993

Increased cell-surface urokinase in advanced ovarian cancer.

Urokinase-type plasminogen activator (uPA), uPA receptors, and cathepsin B were quantitated by using an immunological method, enzyme-linked immunosorbent assay, and amidolytic activity assays in 15 malignant and 10 benign epithelial ovarian tumors. The levels of uPA and uPA receptors, as well as cathepsin B, were found to be higher in membrane preparations obtained from malignant tumors than in those obtained from benign tumors. Acid-treated membranes acquired the ability to bind uPA, indicating that uPA is bound to a specific surface receptor that is not completely saturated. Levels of single-chain uPA (pro-uPA) and high-molecular-weight uPA in membrane preparations were measured by immunoadsorbent-amidolytic assay. The finding of a significant increase in amidolytic activity following activation of uPAs by plasmin suggested that less than half (30-40%) of all membrane immunoreactive uPAs is present in the enzymatically inactive pro-uPA form. In the membranes of malignant tumors, levels of uPA receptor and cathepsin B did not vary with stage of disease. On the other hand, we found that the level of receptor-bound uPA antigen/activity was significantly increased in advanced malignant tumors. Receptor-bound uPA may play an important role in determining invasive potential of tumor cells. Since ovarian cancer cells produce both pro-uPA and cathepsin B, the possibility of activation of tumor cell-derived pro-uPA by cellular protease cathepsin B must be considered.

Antigens, Neoplasm↗
PubMed1993

Adrenal renin is localized in lysosomal granules.

Both renin and cathepsin B were co-localized in identical granules of adreno-cortical cells. At day 16 of gestation, many renin-containing granules were observed and gold particles showed homogeneous intragranular distribution; whereas, those for cathepsin B was distributed heterogeneously. At day 18 of gestation, renin immunoreactivity was decreased or undetectable, whereas cathepsin B was still demonstrated at the same level as on day 16 of gestation.

Adrenal Cortex↗
PubMed1993

A simple method of hybridohistochemistry for detection of renin mRNA in the mouse kidney.

Hybridohistochemistry was applied for the detection of renin mRNA in the mouse kidney with a digoxigenin-labeled probe, synthesized as the sense and antisense RNAs from Ren-1 cDNA in the presence of digoxigenin-dUTP. Renin mRNA was detected in the juxtaglomerular cells located in the vicinity of the glomerular vascular poles of the kidney using the digoxigenin-labeled antisense RNA as a probe. Using the sense RNA as a probe, no signal was detected anywhere. In neighboring serial sections, the same cells reacted immunohistochemically to rabbit anti-mouse submandibular gland renin serum as in hybridohistochemistry. As we used the probe labeled with digoxigenin as a non-radioisotopic marker, there was no need for special handling other than that in immunohistochemistry. It was concluded that the simple procedure given in the present study is useful for the detection of mRNA.

Animals↗
PubMed1993

Distribution of T cell subsets in chicken lymphoid tissues.

The distributions of T cell subsets in chicken lymphoid tissues were investigated immunohistochemically using monoclonal antibodies (Lc-6, Lc-4) with specificity for chicken CD4 and CD8, respectively. In thymic tissues, CD8+ cells were found only in the cortex, while CD4+ cells were detected not only in the cortex but also in the medulla. The cortex just below the capsule demonstrated no immunoreactivity to either antibody. In the cecal tonsile, CD8+ cells were found restrictly in the subepithelial lamina propria. It was noted that the germinal centers were clearly surrounded with many CD4+ cells in the mid and deep portions of the lamina propria. In the spleen, clusters of CD8+ cells were observed only in the red pulp. Most lymphocytes in the periarteriolar lymphatic tissue and perivenous lymphatic tissue showed a CD4-positive reaction. No lymphocyte in the germinal centers reacted with these two monoclonal antibodies. No immunoreactivity for either CD8 or CD4 was detected anywhere else in the bone marrow or bursa of Fabricius. In the case of exposure to the protein antigen (alum-precipitated bovine serum albumin), CD4+ cells were demonstrated in some germinal centers, which were increased in size, while the areas expressing CD8 in the red pulp were decreased in size. These results suggest that the preferential distributions of T cell subsets are inherent in chicken lymphoid tissues.

Animals↗
PubMed1993

Isolation and antibody prevalence of a parapoxvirus in wild Japanese serows (Capricornis crispus).

An epizootic suspected to be caused by parapoxviruses occurred in winter, 1984-85, among wild Japanese serows (Capricornis crispus) with nodular or papular lesions in Gifu Prefecture, Japan. Virus isolations were attempted on 30 animals using bovine fetal testicle cell cultures. Viral agents growing with cytopathic effects were isolated from six animals. The agents were identified as parapoxvirus from electron microscopic findings and physico-chemical characteristics. Antibody prevalence to the isolated agent, named S-1, was examined by enzyme-linked immunosorbent assay. No antibodies were detected among 153 sera obtained during two winters 1981-82 and 1982-83, but one of 189 sera collected in the winter of 1983-84 was positive. In contrast, 75 (32%) of 237 sera had antibodies to S-1 in 1984-85, when the disease was first detected. Antibody prevalences of 1984-85 were highest (39%) in December 1984, the first month of animal capture, and declined gradually to 20% in March 1985.

Animals↗
PubMed1992

Inhibition of in vitro ovarian cancer cell invasion by modulation of urokinase-type plasminogen activator and cathepsin B.

HOC-I ovarian cancer cells express the single-chain form of the urokinase-type plasminogen activator (uPA) and cathepsin B (cath B) on their cell surface. The significance of the expression of cell surface uPA/cath B activity to the invasive potential was examined by preincubating with uPA/cath B-modulating agents in in vitro invasion assay. The anti-uPA monoclonal antibody 394 effectively inhibited invasion in a dose-dependent manner. On the contrary, anti-cath B antibody did not affect the invasive potential of the cells. E-64, a specific inhibitor for cysteine proteases, blocked invasion as effectively as monoclonal antibody 394. The data reveal that the uPA and cysteine proteases contribute significantly to the invasive capacity of the cells. We suggest that the cysteine proteases facilitate the action of uPA, possibly by activating proenzyme uPA produced by cancer cells. Evidence for the role of a cathepsin-uPA activation cascade in HOC-I cell invasion is provided.

Cathepsin B↗
PubMed1992

Morphological and northern blot analysis of juxtaglomerular cells in experimental hydronephrotic mice.

The purpose of this study is to demonstrate the developmental changes of the experimental hydronephrotic kidney using immunohistochemical, histoplanimetrical, and Northern blot techniques. At 1 month after ligation of the ureter, a large number of renin-positive cells were detected immunohistochemically even at a dilution of 1:10,000 in this hydronephrotic kidney; however, there were few renin-positive cells in the non-ligated side. At 6 months after ligation, no difference in reactivity for renin between ligated and non-ligated kidneys was demonstrated. In the morphometrical analysis of the renin-positive region, the numerical value of the ligated side was already increased at 2 weeks, reached the highest value at 1 month, and then decreased gradually to almost the same value as the control kidney by the end of the experiment. On the other hand, the value of the non-ligated side decreased immediately after the unilateral ligation, increased later, and finally reached almost the same value as the control kidney. In the Northern blot analysis, the activity of renin mRNA in the ligated side at 1 month after ligation was markedly higher than that in the non-ligated side. However, the difference between the ligated and the non-ligated sides was not demonstrated at 6 months and the value came to be almost the same as in the non-operated kidney.

Animals↗
PubMed1992

Vascularized fibular graft for reconstruction after resection of aggressive benign and malignant bone tumors.

From 1982 to 1991, 19 patients at Nara Medical University, Kashihara, Japan, underwent resection of aggressive benign and malignant bone tumors, with limb salvage and reconstruction by free vascularized fibula grafts. The patients were followed up for an average of 54 months. The reconstructed site was the jaw in 6 cases, upper extremity in 3, spine in 1, pelvis in 2, and lower extremity in 7. Six patients had aggressive benign lesions, and 13 had malignant lesions. The sizes of the resultant bone defect ranged from 6 to 20 cm, and the lengths of fibular used ranged from 8 to 24 cm. The average time to union was 4.1 months (2-9 months) in the extremities and pelvis. Local recurrence was observed in 3 cases, for whom vascularized fibula grafts were performed for recurrent tumors. In cases of primary untreated tumors, no recurrences occurred. Therefore, this procedure should be performed at the time of primary operation after extensive resection of an aggressive benign or malignant bone tumor.

Adolescent↗
PubMed1992

Characterization and clinical evaluation of tumor-associated antigen CA54/61 identified by monoclonal antibodies MA54 and MA61 in epithelial ovarian cancer.

Monoclonal antibodies (moABs) MA54 and MA61, directed toward the O-linked mucin-type glycoprotein, have been established and showed highly specific reactivity with human ovarian cancer. Fetal intestinal and colonic mucosal cells expressed this antigen and meconium staining was also frequently positive. To investigate the characteristic of an epitopic carbohydrate recognized by these moABs, the reactivity of each moAB with meconium extract was monitored by solid-phase enzyme-linked immunosorbent assay with mono-, di-, and oligosaccharides. MA54 and MA61 react with meconium extract and the reactivities of these moABs are neuraminidase sensitive. Ovine submaxillary mucin had a strong inhibitory activity toward the reaction between meconium extract and MA54 as well as MA61, suggesting that these moABs recognize NeuAc 2-6GalNAc epitope in meconium. The second aim of this study is to investigate the possible application of moABs to diagnose ovarian cancer and to compare these levels with those of the CA125 antigen. While serum CA54/61 antigen levels were elevated in 44.4% of ovarian cancer cases and serum CA125 antigen levels were elevated in 86.7% of the same population, the use of both assays indicated a sensitivity of detection of 97.8% (44 of 45 patients) in the population studied.

Antibodies, Monoclonal↗
PubMed1992

Clinical significance of urokinase-type plasminogen activator (uPA) in invasive cervical cancer of the uterus.

The relationship between the level of urokinase-type plasminogen activator (uPA) and pelvic lymph node metastasis was investigated in 20 patients with invasive cervical cancer of the uterus. Frozen sections from all surgical specimens were stained immunohistochemically by alkaline phosphatase anti-alkaline phosphatase method to detect uPA in cancer tissue. The concentration of uPA, determined immunologically, and the fibrinolytic activity were also examined in supernatants of homogenates of some cancer tissues. uPA was detected immunohistochemically in cancer cells of all specimens. A significant correlation was found between the extent of immunohistochemical staining for uPA and the concentration of uPA determined immunologically in cancer tissues (P less than 0.05). A positive correlation was also found between semiquantitative values determined by immunohistochemical staining for uPA and lymph node metastasis (P less than 0.05). Fibrinolytic activity in cancer tissues was confirmed by casein-plaque assay. These findings indicate that the pro-uPA/uPA contents in cervical cancer tissues are clinically useful for predicting the metastatic potential of these cancers to the pelvic lymph nodes.

Carcinoma, Squamous Cell↗
PubMed1992

An immunoelectron-microscopical observation of mouse juxtaglomerular cells in the case of experimental hydronephrosis.

Changes in juxtaglomerular (JG; renin-containing) cells in experimental hydronephrosis 1 month after ureteral ligation were investigated with immunoelectron-microscopical techniques. Two types of granules, electron dense (D) and lucent (L), were observed. D type granules were labeled more intensely with gold particles than those of L type. Granules intermediate between D and L types and exocytosis of D types were observed. In the cells containing D types exclusively, gold particles were restricted to the granules, whereas in the cells containing both D and L type granules, the particles were scattered throughout the cytoplasmic cytosol. The authors discuss the mechanisms of renin release in JG cells.

Animals↗
PubMed1992

YM-14673, a new thyrotropin-releasing hormone analog, augments long-term potentiation in the mossy fiber-CA3 system of guinea pig hippocampal slices.

Effects of a new thyrotropin-releasing hormone (TRH) analog, N alpha-[[(S)-4-oxo-2-azetidinyl]carbonyl]L-histidyl-L-prolinamide dihydrate (YM-14673), which improves experimentally induced memory dysfunction, on long-term potentiation (LTP) in the mossy fiber-CA3 system, were investigated using guinea pig hippocampal slices. At concentrations of 10(-7) M and 10(-6) M, YM-14673 significantly augmented LTP in a concentration dependent manner. The magnitude of effect of 10(-6) M YM-14673 was similar to that of 10(-6) M TRH. As LTP in the hippocampus is regarded as an elementary process of memory and learning, the augmenting effect of YM-14673 on LTP in the present study may contribute to this drug's ability to remedy memory dysfunction.

Animals↗
PubMed1992

Are there M cells in the cecal tonsil of chickens?

A unique morphological cell type, "microfold or membranous (M) cell-like cell", was detected electron-microscopically in the cecal tonsil epithelium of the chicken. M cell-like cells possessed a few short microvilli of irregular arrangement and a large number of lymphocytes and macrophages wedged into their basal surfaces. Triticum vulgaris was found to bind to M cell-like cells. With horseradish peroxidase (HRP) treatment, M cell-like cells showed an active HRP uptake just as did the neighbouring usual absorptive epithelial cells. No uptake of colloidal carbon particles from the intestinal lumen was recognized in any part of the intestinal epithelium. These results suggest that M cell-like cells of the chicken possess some M cell-characteristic morphological and histochemical features, but that their active uptake of foreign materials is not so developed as in mammalian M cells.

Animals↗
PubMed1992

[Effects of sex hormones and propylthioracil on growth of transplantable rat thyroid tumor with estrogen receptor (ER)].

UNLABELLED: Effects of hormones (E2: estradiol, TP: testosterone) and propylthiouracil (PTU) on the growth of transplantable rat thyroid tumor (F2D1) having estrogen receptors were studied. Rat thyroid neoplasms, induced by N-bis (2-hydroxypropyl) nitrosamine, were inoculated subcutaneously from donor to recipient rats, in order to establish 16 transplantable rat thyroid tumor lines. The grafts were used for histological studies and for the assay of estrogen receptor (ER) and androgen receptor (AR). Of these lines, we designated papillary carcinoma, which was positive for ER (N: 12.5fmol/mg protein, Kd: 0.4nM) but negative for AR, as F2D1. For studies on the effects of sex hormones and PTU on the growth of transplantable tumors, the rats which had been inoculated with tumors were divided into the following 8 groups; (1) Intact, (2) PTU, (3) ovariectomy (OV), and (4) OV + E2 for female, and (5) Intact, (6) PTU, (7) castration (CA), and (8) CA + TP for male. RESULTS: The growth rate of F2D1 in female rats was decreased by OV, but no change was observed in OV + E2 as compared with Intact. CA and CA + TP in male rats did not influence the growth rate. PTU produced a significant increase in the growth rate in both sexes. These results demonstrate that estrogen and PTU act on the growth of ER-positive rat thyroid tumors.

Animals↗
PubMed1992

Comparative study of renin expression in the coagulating glands of C57BL/6 and Balb/c mice.

The comparative localisation of renin in the genital organs, especially in the coagulating glands of male mice of the strains C57BL/6 and Balb/c, was investigated using immunocytochemical, immunoelectron microscopical and Northern blot techniques. Dot-like reactions for renin, of varying diameters, were detected immunocytochemically in the epithelial cells of coagulating glands of C57BL/6 mice, but not in those of Balb/c mice. In both strains, many electron dense granules differing in content and morphology were observed in the epithelial cells of the coagulating glands. Crystalline materials were sometimes contained in these granules. Colloidal gold particles indicating the presence of renin were detected in the electron dense granules of C57BL/6 mice, in which they showed a heterogeneous distribution and were especially located on the crystalline structure. No positive reaction was detected in these crystalline structures in Balb/c mice. Renin mRNA was detected in the coagulating glands of both C57BL/6 and Balb/c mice by Northern blot analysis. However, the expression in C57BL/6 coagulating glands was stronger than that in Balb/c. These findings suggest that renin is synthesised and released in the coagulating glands.

Animals↗