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Biomedical subjects

T Kameda

Publications and source records attributed to T Kameda.

At least 91 records · Page 5Linked to original sources
PubMed1991

Application of gene amplification by polymerase chain reaction to genetic analysis of molar mitochondrial DNA: the detection of anuclear empty ovum as the cause of complete mole.

To investigate the pathogenesis of complete hydatidiform mole (complete mole), we employed a newly developed gene amplification method by polymerase chain reaction (PCR) for the restriction fragment length polymorphism (RFLPs) analysis of extranuclear DNA (mitochondrial DNA) of complete mole. Whole cellular DNA was extracted from six molar tissues and from peripheral blood mononuclear cells of parents. Two hyperpolymorphic regions of mitochondrial DNA, a 1.5-kb-long fragment and a 1.9-kb-long fragment, were selectively amplified from the extracted DNA by the PCR method. The amplification products amounted to over 10 micrograms after 30 cycles of PCR. The PCR products were digested with endonucleases (HaeIII, HinfI, AluI, and TaqI) and then electrophoresed on agarose gel. The electrophoretic pattern of digested DNA showed that the RFLPs of molar mitochondrial DNA coincided with those of the patient, indicating that the mitochondrial DNA of complete mole was inherited from the ovum. As it has been identified that the intranuclear DNA of complete mole is transmitted only from the spermatozoa, our results verify that complete mole results from the fertilization of an anuclear "empty" ovum with normal sperm at the molecular level.

Base Sequence↗
PubMed1991

Analysis of immunoregulatory activity of a choriocarcinoma-derived factor: specific suppression of proliferative process of cell-mediated immune responses including LAK cell generation.

The immunosuppressive activity of a JEG-3 choriocarcinoma-derived factor in human IL-2-dependent T cell responses has been studied, together with its effect on IL-2-independent T cell responses induced by 10 nM TPA. The factor completely suppressed the IL-2-independent proliferative responses of T cells but failed to suppress antigenic expression of activation-associated CD 25 molecules. Further studies examined the effect of the factor on LAK cell generation induced by rIL-2. Recombinant IL-2-induced LAK cell proliferation was observed on Day 4 and Day 5, but not on Day 3. As the factor suppressed the responses of LAK cell proliferation, we tested whether it blocked the generation of Day 3, Day 4 and Day 5 LAK cells. The addition of the factor failed to suppress the generation of Day 3 LAK cells, while it partially suppressed the lytic activity of Day 4 LAK cells and completely suppressed that of Day 5 LAK cells. The data suggest the presence of a heterogeneous pattern for LAK cell generation; one without proliferation, but the other requiring proliferation, to acquire killer activity. Taken together with the evidence that the factor failed to suppress NK activity, the choriocarcinoma-derived factor suppressed only the proliferative events of immunocompetent cells, but inhibited neither their activation nor the differentiation events. This immunosuppressive factor might be involved in the prevention of host-mediated rejection of choriocarcinoma cells or maternal rejection of the fetus.

Choriocarcinoma↗
PubMed1991

Differential mRNA expression of three distinct classes of Fc gamma receptor at the feto-maternal interface.

Heterogeneous expression of three classes of Fc gamma receptor (Fc gamma RI, IIa, IIb, and III) in the human placenta and decidua was examined by Northern blot hybridization and cDNA amplification analysis by polymerase chain reaction. Messenger RNA of Fc gamma RI, IIa and III genes were consistently expressed in the human placenta in all trimesters of gestation. The transcripts of the Fc gamma RIIb gene, on the other hand, dramatically increased in placentae at the second and third trimesters. This characteristic expression of Fc gamma RIIb after 20 gestational weeks was confirmed by sequential cDNA amplification analysis. Fc gamma RI, IIa and III mRNAs, but not Fc gamma RIIb, were also detected in the human decidua. Interestingly, while Fc gamma R mRNA could be induced in uterine endometrium by pseudopregnancy therapy using estrogen and progesterone, there was no detectable mRNA in hormone-unprimed normal endometrium. These findings suggest that Fc gamma Rs expressed at the feto-maternal interface can be transcriptionally regulated by sex steroid hormones as multifunctional molecules. In addition, the Fc gamma RIIb molecule is predominantly produced by placental tissues after the mid-trimester of gestation and possibly plays an important role in the transport of IgG molecules from mother to fetus.

Antigens, CD↗
PubMed1991

Probabilistic assessment of the HLA sharing of recurrent spontaneous abortion couples in the Japanese population.

In spite of a number of investigations, the concept of human leukocyte antigen (HLA) sharing in recurrent spontaneous abortion (RSA) couples remains controversial. We introduced the basal antigen sharing rate (BSR) by the original mathematical approach using the gene frequency of all HLA specificities derived from our regional control population and applied this parameter for the comparison with RSA couples. RSA couples were classified into three subgroups; primary (3 or more consecutive abortions), secondary (3 or more consecutive abortions after 1 live birth), and potential (2 consecutive abortions) aborters. No significant differences between the HLA class I sharing rates (one or more antigens shared on a single locus) of the all RSA subgroups and the calculated BSRs were observed. In the HLA-DR and DQ loci, on the other hand, the antigen sharing rates of primary aborters were significantly higher than BSRs (p less than 0.01/DR, p less than 0.05/DQ). While potential aborters showed a result similar to that of the primary aborters, no significant antigen sharing of HLA class II was observed in secondary aborters. Our data suggest that BSR is a useful parameter for detection of significant HLA sharing in regional populations and the consecutive abortions that occurred primarily are certainly relevant to HLA class II sharing.

Abortion, Spontaneous↗
PubMed1991

Trophoblast-derived interleukin-1 (IL-1) stimulates the release of human chorionic gonadotropin by activating IL-6 and IL-6-receptor system in first trimester human trophoblasts.

Interleukin-1 (IL-1) has a unique activity to stimulate the release of multiple hormones in a number of human and murine endocrine systems. IL-6 also expresses such activities by activating IL-6-receptor (R)-mediated signal transduction pathways. Since the placenta produces both of these cytokines and endocrine hormones such as hCG, we investigated how these cytokines regulate hCG release by normal trophoblasts. Trophoblasts purified by Percoll density gradient released hCG from 120 min after stimulation with recombinant (r) IL-1 alpha, and its release was dependent on the rIL-1 alpha concentration used. The rIL-1 alpha-stimulated trophoblasts released a molecule with IL-6 activity antecedently, as determined by an IL-6-dependent cell line, MH60.BSF2 cells. The IL-6 identity of the released molecule was confirmed by goat anti-IL-6 antiserum. rIL-1-mediated hCG release from trophoblasts was completely abrogated to the basal level by pretreatment of the trophoblasts with PM1, an anti-IL-6-R monoclonal antibody. Identical results were observed with rIL-1 beta. These results showed that rIL-1-induced hCG release was totally dependent on IL-6- and IL-6-R-mediated signal transduction in human trophoblasts. The presence of peripheral monocytes in the purified trophoblast fraction, however, induced a rapid decrease in IL-6 and hCG release after their maximal release, suggesting some regulatory interaction between trophoblasts and the monocytes. In contrast, rIL-1-mediated enhancement of IL-6 and hCG secretion by purified trophoblasts was no longer observed at 24 h compared with that of the unstimulated trophoblasts, while spontaneous hCG secretion was significantly inhibited by pretreatment of trophoblasts with PM1. The results showed that IL-6 and hCG secretion might also be regulated by a number of agents besides IL-1, and that hCG secretion as well as its release is dependent on IL-6 and IL-6-R system in trophoblasts.

Antibodies↗
PubMed1991

[Histologic examinations of internal mammary artery, saphenous vein and aorta specimens collected during heart surgery].

133 patients with coronary heart disease were treated surgically. 60 patients had Internal Mammary Artery (IMA) grafting performed together with saphenous vein grafts (IMA group), another 70 patients had saphenous vein grafts only (SVG group). Material for histological examination was intraoperatively taken from saphenous vein and ascending aorta and in IMA group also from the distal part of internal mammary artery. The intensity of atherosclerosis was estimated with 5-grade scale from 0 to 4 (0-no atherosclerosis, 1-minimal, 2-insignificant, 3-moderate, 4-pronounced). To visualize and to assess the blood flow through the internal mammary artery Digital Subtraction Angiography (DSA) was performed between day 6 and day 8 postoperatively in the IMA group. Results obtained were correlated with the intensity of atherosclerosis estimated histologically and the numeric data were statistically analysed. In the IMA grafts mean atherosclerosis intensity was 0.94 which is the evidence of minimal atherosclerotic changes. In saphenous vein the corresponding value was in the IMA group 2.14 and in the SVG group 2.17, in aortic scraps 2.64 in the IMA group and 2.73 in the SVG group. Patients in the SVG group were average 8.4 years older than in the IMA group. The difference is statistically significant. Despite the age difference, the intensity of atherosclerosis was not statistically different in aortic and saphenous vein scraps. Among 63 patients in the IMA group in 31 patients (49.2%) no atherosclerosis was found during histological examination and in 32 patients (50.8%) changes ranged from minimal to moderate. There were no IMA grafts with the pronounced atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Expression of ERBB2 in human gastric carcinomas: relationship between p185ERBB2 expression and the gene amplification.

The expression of p185ERBB2 in a total of 34 human gastric carcinoma tissues as well as in corresponding normal mucosa was examined by Western blotting. More than 70% of both tumor tissues and normal mucosa showed p185ERBB2 expression at various levels. Eighteen (55%) cases revealed higher levels of p185ERBB2 in the tumor than in normal mucosa, while 13 (38%) cases showed lower levels in the tumor tissues. Higher expression of p185ERBB2 was frequently observed in well differentiated adenocarcinomas, with the incidence between well differentiated type and poorly differentiated type being significantly different (P less than 0.05). Comparative immunohistochemical analysis revealed the consistent results with p185ERBB2 expression obtained by Western blotting in well differentiated adenocarcinomas. Of the 34 cases, three well differentiated adenocarcinomas had extremely high levels of p185ERBB2. ERBB2 gene was amplified in two of the three tumors, but the amplification differed by the tumor site from where the sample was obtained. Another tumor which showed an extremely high level of p185ERBB2 but no gene amplification demonstrated a high level of binding protein to the TATA box that is located in the promoter of the ERBB2 gene. A high level of TATA-binding protein was also detected in gastric carcinoma cell lines which contain a single copy of ERBB2 gene and a high expression of p185ERBB2.

Blotting, Northern↗
PubMed1990

pp60c-src protein kinase activity in human gastric carcinomas.

We examined pp60c-src protein kinase activity in human gastric carcinoma cell lines and gastric carcinoma tissues as well as normal mucosa. pp60c-src kinase activity was detected in all 5 carcinoma cell lines at various levels. Of 16 gastric carcinoma tissues, 8 showed higher pp60c-src kinase activity in tumor tissues than in corresponding normal mucosa. However, the levels of expression of pp60c-src detected by Western blotting were not always consistent with the activities of pp60c-src protein kinase. These findings suggest that the increase in pp60c-src protein kinase activity might be brought about by post-translational changes.

Blotting, Northern↗
PubMed1990

In vitro and in vivo production of interleukin-6 by fetal mononuclear cells.

We examined the functional activity of cord mononuclear cells (MNCs) to produce interleukin (IL)-6 in vitro and in vivo. We stimulated fetal T-cell, B-cell, and macrophage fractions with mitogens. The supernatant of each stimulated cord cell fraction contained a comparable amount of IL-6 to that of each adult cell fraction activated similarly, suggesting functional maturity of cord MNCs' ability to produce IL-6. We then examined fetal cells' activities to produce IL-6 in response to perinatal infections, especially to intraamniotic infections (IAI). Among the cord MNCs from fetuses with IAI, macrophages were major cells producing IL-6. The serum IL-6 level in the fetuses with IAI was elevated, but it decreased to normal levels after antibiotic treatment; this finding indicates that IL-6-mediated host defense mechanisms by cord MNCs are triggered by perinatal infections.

Amniotic Fluid↗
PubMed1990

Induction of growth factor-receptor and metalloproteinase genes by epidermal growth factor and/or transforming growth factor-alpha in human gastric carcinoma cell line MKN-28.

We examined the effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) on EGF receptor (EGFR) phosphorylation and the expression of mRNAs for oncogenes, growth factors, their receptors and metalloproteinase genes by MKN-28 gastric carcinoma cells which express EGF, TGF-alpha and EGFR genes. Both EGF and TGF-alpha stimulated EGFR phosphorylation, EGF and TGF-alpha induced FOS, MYC and ERBB-2 oncogene expression. Interestingly, EGF increased the expression of mRNAs for TGF-alpha and EGFR. On the other hand, TGF-alpha increased TGF-alpha mRNA but decreased the expression of mRNAs for EGFR and TGF-beta. Furthermore, mRNAs for interstitial collagenase, stromelysin and procollagen type I genes were also enhanced after treatment with EGF and TGF-alpha. These results indicate that EGF and TGF-alpha successively evoke cascade phenomena which favor tumor progression, invasion and extracellular matrix formation, acting as autocrine growth regulators for gastric carcinomas.

Carcinogens↗
PubMed1990

Effect of epidermal growth factor on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of epidermal growth factor (EGF) on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitro-soguanidine (MNNG) was studied. Male Wistar rats given MNNG for 30 weeks in drinking water (80 micrograms/ml) were treated with s.c. injections of human EGF (10 micrograms/kg, once daily) at various stages of the carcinogenesis. Four (30.8%) out of 13 rats treated with EGF immediately after cessation of the MNNG treatment had stomach tumors including one adenocarcinoma, one adenoma and two carcinoids. No stomach tumor was found in rats treated with MNNG alone or in those treated with MNNG and EGF for different periods such as synchronously for 10 weeks, for 30 weeks or throughout the experiment. These findings suggest a possible enhancing effect of EGF on stomach carcinogenesis in rats.

Animals↗
PubMed1990

Prominent meningeal enhancement adjacent to meningioma on Gd-DTPA-enhanced MR images: histopathologic correlation.

To assess tissue changes responsible for enhancement of the meninges adjacent to meningiomas on magnetic resonance (MR) images, the authors correlated the MR imaging characteristics of meningeal lesions seen before and after administration of gadolinium diethylenetriamine-pentaacetic acid (DTPA) with the appearance of these lesions on contrast material-enhanced computed tomographic (CT) images and with histopathologic findings in four patients. Histopathologic examination of meninges showed increased loose connective tissue, hypervascularity, and dilated vessels. There was neoplastic infiltration of the dura mater in two patients but it was restricted to the immediate junction of neoplasm and dura mater, with maximum peripheral extension within 1 mm of the tumor margin. In both patients the meninges were enhanced far beyond the neoplastic infiltration. The other two patients showed no infiltration of dura mater. These findings suggest that pathologic enhancement of meninges adjacent to meningioma after administration of Gd-DTPA mainly represents reactive changes to the neoplasm and does not necessarily indicate neoplastic involvement.

Female↗
PubMed1990

Trophoblast-derived interleukin-6 (IL-6) regulates human chorionic gonadotropin release through IL-6 receptor on human trophoblasts.

We examined the capacity of trophoblast-derived interleukin-6 (IL-6) to stimulate secretion of placental hormones, including hCG. IL-6 stimulated hCG secretion by trophoblasts to a level similar to that stimulated by a GnRH analog. The analog, however, released hCG by an IL-6-independent mechanism because PM-1, a monoclonal antibody specific for IL-6 receptors (R), failed to block GnRH-mediated responses, but completely blocked IL-6-mediated hCG secretion, suggesting the existence of two distinct regulatory pathways for hCG release. Immunohistochemical analysis with another IL-6-R-specific antibody, MT-18, showed that IL-6-R was located only on the trophoblast layer of the placenta. Our data revealed the existence of a local regulatory network by which trophoblast-derived IL-6 interacts with IL-6-R on the trophoblasts, resulting in hCG release. Thus, two different regulatory networks, an IL-6 and IL-6-R system and a GnRH and GnRH-R system, regulate hCG release by human trophoblasts independently.

Antibodies, Monoclonal↗
PubMed1990

[A study of dental soldering. (10) The temperature distribution of infra-red soldering machine].

The purpose of this study is to measure the temperature distribution of focused energy by infra-red soldering machine. The result indicate following. 1. The three dimensional heating area is an ellipse shape, and soldering area is about 10 mm in diameter centering around the focus. 2. Temperature adjustment of INFRARED (NEY Co.) is to use Powerlevel, and of BEAMWERDER (YOSHIDA Co.) is adjusting the height of the turn table. 3. When soldering with focused energy with infra-red machine, it is adequate to solder at the focused level or the upper level, after pre-heating of the soldering objects at the lower level.

Dental Soldering↗
PubMed1989

Establishment and characterization of cell line SFCC from clear cell adenocarcinoma of the uterine cervix.

A human cervical clear cell adenocarcinoma cell line was established and named SFCC. The tumor cells were obtained from ascites of a 39-year-old woman who underwent a radical hysterectomy. She had no history of exposure to diethylstilbestrol (DES). The histologic feature of the tumor cells at autopsy showed abundant clear cytoplasm with diastase digested glycogen granule growing in solid nest and tubular pattern. SFCC cells were continuously propagated in vitro during the past 29 months and grown in a monolayered sheet with a doubling time of about 67 hours. SFCC cells resembled the structure of the original tumor and had abundant glycogen granules, lipid droplets in the cytoplasm, and numerous microvilli. Immunohistochemically, SFCC cells had carcinoembryonic antigen (CEA) immunoreactivity in some parts of the cell population. Moreover, they had a relatively high amount of progesterone receptor (20.0 fmol/mg protein; kd, 6.6 nM) but did not have either an estrogen receptor or EGF receptor. The SFCC cell line secreted a high content of tissue peptide antigen (TPA) into the medium, indicating that the SFCC cell line is useful for analyzing the progesterone receptor and TPA production in clear cell adenocarcinoma of uterine cervix.

Adenocarcinoma↗
PubMed1989

Demonstration of functional immaturity of signal transduction pathways in human cord T cells.

We examined the nature of cytoplasmic signal transduction pathways in cord blood T cells by stimulating them with tumor promoter (TPA) and calcium ionophore (A23187). Costimulation of T cells with TPA and A23187 induced optimal proliferative responses on Day 2 in cord T cells but on Day 4 in adult T cells. The maximal responses observed in cord T cells were much less than those of adult T cells, whereas the Con A-induced proliferative responses of these cells showed no significant differences. The reduced responses of cord T cells were due to their lower efficiency in activating the cellular events in T cell activation and proliferation phase, because cord T cells have significantly less ability than adult T cells to express IL-2 receptor as well as HLA-DR and produce IL-2 molecules, thereby inducing proliferation. These data show immature characteristics of intracellular signal transduction pathways in cord T cells, which are directly related with the functional immaturity of cord T cells.

Adult↗
PubMed1989

Analysis of site of action of a choriocarcinoma-derived immunoregulatory factor on IL-2-mediated T cell responses.

We have investigated the functional ability of a choriocarcinoma-cell-derived factor to block human T cell responses and the factor's immunoregulatory site of action on the T cell signal transduction pathway. The factor completely suppressed human T cell responses activated by phorbol ester and calcium ionophore, reagents which strongly stimulate IL-2-mediated T cell responses. It failed to inhibit CD 25 expression and IL-2 production by T cell blasts in the T cell activation phase, but completely blocked recombinant IL-2-induced proliferation of T cell blasts in the T cell proliferation phase. Absorption experiments with the factor and Con A-induced T cell blasts as well as [125I]IL-2 binding experiments with T cell blasts revealed that the factor acted on the physiological events occurring after IL-2-mediated stimulation of IL-2 receptor complexes, demonstrating no interaction of the factor with either IL-2 molecules or IL-2 receptor complexes. Moreover, it suppressed murine IL-2 dependent T cell line proliferation, suggesting the presence of common pathways in human and murine T cell proliferation. The biological and immunological significance of the factor during pregnancy and in the immunosuppressed tumor-bearing hosts are discussed.

Calcimycin↗