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Biomedical subjects

J Fujimoto

Publications and source records attributed to J Fujimoto.

At least 217 records · Page 12Linked to original sources
PubMed1995

Are human herpes viruses or measles virus associated with esophageal achalasia?

In order to test the hypothesis that esophageal achalasia may be due to neurotropic viral damage to the esophageal myenteric plexus, esophageal tissue with or without achalasia was analyzed by polymerase chain reaction for the presence of human herpes virus DNA or measles virus RNA. The DNA and RNA were extracted from the esophageal muscle of 12 patients with achalasia and six patients with upper esophageal carcinoma. Peripheral blood mononuclear cells from eight adult volunteers and two samples of umbilical blood mononuclear cells were also used as controls. PCR amplification with a pair of primers specific for herpes simplex type 1 and 2 viruses identified 92-bp fragments in nearly all specimens, including those without achalasia. Each 92-bp fragment was confirmed to be identical to a single herpes simplex virus sequence by automated DNA sequence analysis. No amplification for five other herpes viruses or measles virus was detected. Therefore, a specific viral etiology for achalasia was not identified in this study.

Adult↗
PubMed1995

Expression of corticosteroid-binding globulin mRNA in human uterine endometrial cancers.

Since it has been demonstrated that corticosteroid-binding globulin (CBG) plays a role in intracellar steroidal actions in target cells, the expression of CBG mRNA as the measure of CBG expression was investigated in human endometrial cancers in order to assess the biological implications of CBG. The level of CBG mRNA was analyzed using competitive reverse transcription-polymerase chain reaction-Southern blot analysis. While the level of CBG mRNA was significantly (P < 0.01) higher in secretory phase endometrium than in early and late proliferative phase endometrium, the level of CBG mRNA tended to decrease with advanced dedifferentiation of endometrial cancers as compared to normal endometrium. These results suggest that dedifferentiation of endometrial cancers induces a reduction in intracellular CBG synthesis.

Adult↗
PubMed1995

Danazol decreases transcription of estrogen receptor gene in human monocytes.

1. Administration of danazol for over one month reduced the levels of estrogen receptor (ER) and its mRNA to approximately 50 and 20%, respectively in monocytes. 2. Danazol did not alter the degradation rate of ER mRNA in monocytes. 3. Danazol decreased the transcription rate of ER gene to approximately 50% in monocytes in a run-on assay. 4. Danazol may release estrogen predominance via the reduction of transcription for ER gene, which leads to the reduction of ER mRNA and ER expressions in monocytes.

Adult↗
PubMed1995

Expression of sex hormone-binding globulin mRNA in human endometrial cancers.

To more fully understand the role of sex hormone-binding globulin (SHBG) on the intracellular steroidal action in endometrial cancers, we investigated the expression of SHBG mRNA as the substitute of SHBG expression in human endometrial cancers. In the present study, the levels of SHBG mRNA were analyzed using competitive reverse transcription-polymerase chain reaction (RT-PCR)-Southern-blot analysis. The higher level of SHBG mRNA tended to be expressed in the normal secretory and late proliferative phase endometrium > early proliferative phase endometrium > well differentiated adenocarcinoma of the endometrium (G1) > moderately differentiated adenocarcinoma (G2) > poorly differentiated adenocarcinoma (G3), in the order shown. These studies indicate that endometrial cancer cells might synthesize intracellular SHBG to conserve their estrogen-dependent properties. Further, it indicates that endometrial cancer cell synthesis of SHBG mRNA is lost as these cells undergo de-differentiation.

Adenocarcinoma↗
PubMed1995

Estrogen induces c-Ha-ras expression via activation of tyrosine kinase in uterine endometrial fibroblasts and cancer cells.

Endometrial fibroblasts derived from uterine endometrium as controls and endometrial cancer cells (Ishikawa and HHUA cells) were used to analyze the manner of induction of c-Ha-ras transcripts in endometrial cancers, some of which are estrogen-dependent in growth. Estrogen increased c-Ha-ras expression and tyrosine kinase (TK) activity in fibroblast and Ishikawa cells, but not in HHUA cells. Progesterone diminished c-Ha-ras expression and tyrosine kinase (TK) activity induced by estradiol in the fibroblasts, but not in Ishikawa cells, which persistently overexpressed c-Ha-ras. In these cells, epidermal growth factor (EGF) increased c-Ha-ras expression as did estradiol. Pretreatment with tyrphostin, an inhibitor of TK, abolished estrogen-inducible overexpression of c-Ha-ras. The combination of both estradiol and EGF at maximum effective concentration exerted no additive or synergistic effect on induction of c-Ha-ras expression. In conclusion, persistent activation of TK might lead to overexpression of c-Ha-ras in some endometrial cancer cells under estrogen predominant milieu, which might be associated with the transformation or growth potential.

Adenocarcinoma↗
PubMed1995

Levels of sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) messenger ribonucleic acid (mRNAs) in ovarian endometriosis.

Recently, much evidence has indicated that sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) play a role in the intracellular action of sex steroids in target cells. In the present work, expression of SHBG mRNA and CBG mRNA was demonstrated in tissues of human normal endometrium and pelvic endometriosis, using the reverse transcription-polymerase chain reaction (RT-PCR). SHBG mRNA levels were higher in pelvic endometriosis than in normal endometrium (P < 0.02), while CBG mRNA levels were lower than in normal endometrium (P < 0.05). The SHBG mRNA/CBG mRNA ratio was significantly higher in pelvic endometriosis than in normal endometrium (P < 0.01). These findings suggest that overexpression of intercellular SHBG in endometriotic tissues results in the formation of the estrogen-predominant milieu, since SHBG-bound estrogen is considered to be protected from the metabolism in liver and available in endometrial cells, thereby assisting the development of the pelvic endometriosis.

Adult↗
PubMed1995

Estrogen induces the expression of c-fos and c-jun genes in fibroblasts derived from human uterine endometrium.

The ratio of membrane/cytosolic protein kinase C (PKC) activity and the levels of c-fos and c-jun expressions in uterine endometrial fibroblasts were increased and reached peak levels with the administration of estradiol, but were partially diminished by the addition of progesterone. The response of c-fos was earlier than that of c-jun. Twelve-0-tetradecanoylphorbol-13-acetate (TPA) increased c-fos and c-jun expressions in endometrial fibroblasts as estradiol did, and pretreatment with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7) reduced the estrogen-inducible c-fos and c-jun expressions. Therefore, it is suggested that oncogenes c-fos and c-jun in uterine stromal cells might be induced by estrogen partly via PKC, involving the interplay of the anti-estrogenic effect of progesterone, and there might be a cross talk between estrogen and PKC stimulants for c-fos and c-jun expressions.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Enzymatic release of 5-formyluracil by mammalian liver extracts from DNA irradiated with ionizing radiation.

To identify a repair enzyme for 5-formyluracil (5-FU) caused by ionizing radiation in DNA, we used a radiolabelled product-release assay for this thymine-damaged substrate. Double-stranded poly(dA-dT)-poly(dA-dT) was radiolabelled by nick translation with [2-14C]-thymidine triphosphate. The DNA was irradiated with X-rays and incubated with cell extract from mouse liver. Radiolabelled products released from the irradiated DNA into an ethanol-soluble fraction were analysed by reversed-phase hplc. Released 5-FU was detected as a free base during reaction with the cell extract. 5-Formyl-2'-deoxyuridine was not detected in the ethanol supernatant. Boiling the extract at 97 degrees C for 15 min completely abolished its ability to release 5-FU. Similar enzymatic activity was observed with rat liver extract. These results demonstrated that mammalian cells have enzymatic activity to release 5-FU from DNA.

Animals↗
PubMed1995

Novel monoclonal antibody reactive with thrombin-sensitive 74-kDa glycoproteins present on platelets and megakaryocytes both from mouse and rat.

A monoclonal antibody (designated 1C2) that reacts only with mouse platelets and megakaryocytes among hematopoietic cells was established by immunizing mouse platelets to an Armenian hamster. 1C2 reactive mouse molecule (1C2 antigen) was a surface glycoprotein with molecular weight of 74 kDa. Side by side comparison revealed that 4A5, a rat monoclonal antibody against mouse platelet, immunoprecipitated the identical molecule to 1C2 antigen. Of particular interest, 1C2 also labeled rat tissues with an identical pattern to that of mouse tissues and recognized a 74-kDa protein from rat platelets. Reactivity of 1C2 to mouse and rat platelets decreased when they were treated with thrombin. Following thrombin treatment of mouse platelets, 1C2 reactive 69-kDa protein appeared in the supernatants. Mouse and rat 1C2 antigens purified on 1C2-coated beads were cleaved by thrombin to generate 69-kDa fragments, establishing that 1C2 antigen is a direct substrate for thrombin. 1C2 is the first antibody to platelets and megakaryocytes of mouse and rat whose reactive molecule is well characterized, i.e., substrate for thrombin. 1C2 can be a useful tool in studying megakaryocytopoiesis and thrombopoiesis in rodent systems.

Animals↗
PubMed1995

Expression of progesterone receptor form A and B mRNAs in gynecologic malignant tumors.

This study was designed to examine the biological implication of progesterone receptor (PR) forms A and B mRNA expressions in gynecologic cancers. The ratio of PR form A to form B in mRNA expression was approximately 1:1 in all endometria studied. The predominant expressions of form B transcript occurred in 6 out of 7 cases of advanced stages (stages III and IV) in ovarian cancers, in 5 out of 9 cases of cervical cancers, and in 5 out of 11 cases of endometrial cancers. In conclusions, the dominancy of PR form B mRNA expression might be associated with the expression of a malignant phenotype in gynecologic cancers, and advanced clinical stage in ovarian cancers, suggesting a biological marker of malignant phenotype in these three types of cancer cell.

Adult↗
PubMed1995

Induction of M-CSF receptor and its mRNA, and activation of tyrosine kinase in peripheral monocytes by oestradiol-17 beta and progesterone.

In monocytes at the secretory (oestrogen-progesterone dominant) phase of the menstrual cycle, expression of c-fms and macrophage colony-stimulating factor (M-CSF) receptor and activity of tyrosine kinase (TK) were increased by oestradiol with or without progesterone. In vivo, oestrogen may induce expression of c-fms and M-CSF receptor as well as the activation of TK in monocytes under the milieu of the secretory phase. Alternatively, cells of monocyte lineage during the secretory phase might, via various factors, obtain the potency to induce the expression and the function of M-CSF receptors, this potency being effected by oestrogen. Macrophages in peritoneal fluid in pelvic endometriosis (oestrogen predominant) might be activated during the secretory phase of the menstrual cycle, causing infertility.

Adult↗
PubMed1995

Oestrogen induces c-Ha-ras expression in the fibroblasts derived from human uterine endometrium.

In this preliminary study, fibroblasts derived from uterine endometrium as a substitute for normal endometrial stroma were used to analyse the stromal role in uterine endometrium, which depends on oestrogen for growth. C-Ha-ras expression and tyrosine kinase (TK) activity in the fibroblasts were increased by oestradiol, and the increase was diminished by progesterone. Epidermal growth factor (EGF), an activator of TK, also increased c-Ha-ras expression. The combination of both oestradiol and EGF at maximum effective concentration exerted no additive and synergistic effect on induction of c-Has-ras expression. Pretreatment with tyrphostin, an inhibitor of TK, abolished the oestrogen-inducible expression of c-Ha-ras. Oestrogen might lead to rapid induction of c-Ha-ras expression in endometrial stroma, at least in part, via the activation of TK for the early stages of oestrogen dependent growth in endometrium.

Adult↗
PubMed1995

Non-phenotypic detection of osteopetrotic (op/op) mutation by using PCR-SSCP analysis.

Mice homozygous for recessive mutation osteopetrosis (op/op) on chromosome 3 provide a unique model to study the mechanism of haematopoiesis in conjunction with bone formation. Based on the DNA sequence data recently reported, we established a PCR-SSCP (polymerase chain reaction--single strand conformation polymorphism) assay which identifies an amplified fragment having an insertional point mutation present in macrophage colony-stimulating factor (M-CSF) gene of op/op mice. With this assay, three genotypes, op/op, +/op, and +/+ can be distinguished. Although heterozygous (+/op) and normal (+/+) mice could not be discriminated phenotypically, we could generate op/op mutant mice starting from a single heterozygous (+/op) mouse using only the PCR-SSCP aided screening method. This assay will permit introduction of the op mutant into any strain to generate a new animal model to study the cytokine network and haematopoiesis.

Animals↗
PubMed1995

Expression of sex hormone-binding globulin mRNA in human ovarian cancers.

To know the role of sex hormone-binding globulin (SHBG) in the intracellular steroidal actions in human ovarian cancers, the expression of SHBG mRNA as a substitute for intracellular SHBG expression was investigated in normal ovarian tissues and ovarian tumors. In the present study, we used competitive reverse transcription-polymerase chain reaction-Southern blot analysis to evaluate SHBG mRNA levels. The expression of SHBG mRNA was detected in all normal ovaries and benign and malignant ovarian tumors analyzed. There were no significant differences in the mean SHBG mRNA levels among the three types of tissue. The expression in normal ovaries was significantly higher (p < 0.01) in premenopause, suggesting the predominance of a sex steroid hormone effect on ovarian SHBG synthesis. Relative overexpression of SHBG mRNA was observed in six out of 22 cases (27%) of ovarian cancer (three cases of endometrioid adenocarcinoma, two cases of serous cystadenocarcinoma and one case of mucinous cystadenocarcinoma) in comparison with normal ovaries and benign ovarian tumors. There was no difference in expression among the clinical stages of ovarian cancers. These data suggest that normal human ovaries and ovarian tumors might synthesize SHBG intracellularly, ovarian cancers might conserve an estrogen-associated property via SHBG and the regulation of intracellular SHBG expression might be changed in some cancers.

Adult↗
PubMed1995

Effects of danazol and medroxyprogesterone acetate on estrogen-(estradiol and estriol) specific binding sites in rabbit uterus.

In rabbit uterus, the presence of separate specific binding sites for not only estradiol but also estriol has been proposed. These sites may be correlated with an antiestradiol effect. Therefore, this study was designed to investigate the effect of antiestrogenic agents such as danazol and medroxyprogesterone acetate (MPA), especially on the estriol binding sites. Danazol and MPA in combination with estradiol were administered subcutaneously to immature female rabbits daily for 10 days, and resulted in a significant (p < 0.05) decrease in uterine weight and estradiol binding sites in the uterus. Treatment with MPA significantly (p < 0.05) decreased the level of estriol binding sites, but treatment with danazol resulted in this to a minimal extent in the uterus primed by estradiol. MPA did not bind to estradiol and estriol binding sites, while danazol at a high concentration bound to estriol binding sites with some affinity, but not to estradiol binding sites in the uterine cytosol of estrogen-primed rabbits. These results suggest that within the antiproliferative effect of danazol and MPA (an antiestrogenic action on estrogen-stimulated uterine growth) there are likely to be specific differences between some of the possible mechanisms of danazol and MPA in their action at the estriol binding site.

Animals↗
PubMed1995

Biological implications of estrogen and androgen effects on androgen receptor and its mRNA levels in human uterine endometrium.

It has been shown that some effects of testosterone are different from those of its 5 alpha-reduced metabolite, dihydrotestosterone. Briefly, activities of testosterone might be related to cellular differentiation, whereas dihydrotestosterone acts on cellular proliferation. The number of testosterone binding sites in the uterine endometrium was increased by estradiol dipropionate, and this increase was down-regulated by testosterone cypionate. Dihydrotestosterone-specific binding sites in the endometrium were not modulated by estradiol dipropionate and testosterone cypionate. The dissociation constants of the binding sites for testosterone and dihydrotestosterone were not altered by these steroids. Estradiol dipropionate with or without testosterone cypionate induced androgen receptor mRNA expression in the endometrium. In conclusion, testosterone might predominantly affect cellular differentiation in the endometrium.

Adult↗
PubMed1995

Sex hormone-binding globulin and corticosteroid-binding globulin mRNA levels in infertile women with luteal phase deficiency.

This study was designed to investigate the biological significance in intracellular expression of sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) mRNA in uterine endometrium with luteal phase deficiency (designated as out-of-phase endometrium or low serum progesterone level). The levels of such mRNAs were measured by the quantitative reverse transcription-polymerase chain reaction. Under the normal serum 17 beta-estradiol and progesterone levels in the mid-luteal phase, the levels of SHBG and CBG mRNAs in the out-of-phase endometria were not significantly different from those in the normal endometria. On the other hand, SHBG and CBG mRNA levels in the endometria of low serum midluteal progesterone level were significantly (p < 0.05) reduced and raised, respectively, compared with normal levels. These findings suggest that the synthesis of endometrial steroid-binding proteins in the out-of-phase endometrium is conserved, as that in the in-phase endometrium, whereas the decreased progesterone level might up-regulate CBG expression with down-regulation of SHBG expression.

Adult↗