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Biomedical subjects

R Iizuka

Publications and source records attributed to R Iizuka.

At least 73 records · Page 4Linked to original sources
PubMed1989

A monoclonal antibody (MSN-1) against a newly established uterine endometrial cancer cell line (SNG-II) and its application to immunohistochemistry and flow cytometry.

To determine a phenotypic difference between normal endometrium and endometrial adenocarcinoma, a new monoclonal antibody (MSN-1) was produced by immunizing a new endometrial cancer cell line (SNG-II), which was established in 1981 from a 43-year-old Japanese woman with stage II uterine endometrial cancer. MSN-1 recognized the Lewis-b carbohydrate moiety on the cell surface glycolipid and seldom reacted immunohistochemically with normal endometrium but with about 90% of endometrial cancer cases. By application of MSN-1 to flow cytometry, the possibility of differentiating endometrial normal cells from cancer cells was demonstrated.

Adenocarcinoma↗
PubMed1989

Menstrual cycle-associated alteration of sulfogalactosylceramide in human uterine endometrium: possible induction of glycolipid sulfation by sex steroid hormones.

The human uterine endometrium is a tissue in which cell proliferation and differentiation are strictly controlled by sex steroid hormones, and these hormone-controlled cellular events occurring in association with the menstrual cycle of the uterine endometrium should be accompanied by characteristic molecular and metabolic changes. To characterize the menstrual cycle at the molecular level, we analyzed the glycolipids of human uterine endometrium in the proliferative and secretory phases of the menstrual cycle. Neutral glycosphingolipids from uterine endometrium comprised globo-series glycosphingolipids, such as GlcCer, LacCer, Gb3Cer, and Gb4Cer, and the relative concentrations remained constant in the two phases. However, in the case of acidic glycosphingolipids, although the concentrations of sialoglycosphingolipids remained at constant levels in the two phases, sulfatide, I3-SulfoGalCer, dramatically increased from the proliferative to the secretory phase, amounting to 7-17 nmol/g dry weight in the proliferative phase and 115-245 nmol/g dry weight in the secretory phase. Since sulfatide was the only glycolipid that changed in association with the menstrual cycle, it is likely that the sulfotransferase responsible for the synthesis of sulfatide might be induced by sex steroid hormones, estrogen and progesterone, and that sulfatide might play an essential biological role in the secretory phase of the menstrual cycle in the uterine endometrium.

Cerebrosides↗
PubMed1989

[An arginine esterase in the human sperm].

Human sperm was highly purified by the use of a discontinuous Percoll density gradient placed in an innercolumn of a centrifugation tube. Seminal plasma contamination was only 0.0008 percent in the purified sperm. A new basic arginine ester hydrolyzing enzyme with a weak affinity for lima bean trypsin inhibitor (LBTI) Cellulofine column was found in the purified human sperm, and the characteristics of this enzyme were found to be different from those of human acrosin.

Calcium Chloride↗
PubMed1989

Mechanism of LH release in cultured rat pituitary cells.

To investigate the mechanisms of the synthesis and the release of gonadotropin, rat anterior pituitary cells were stimulated in vitro with luteinizing hormone releasing hormone (LH-RH), [D-Ser(tBu)]6 des-Gly-NH2(10) ethylamide (Buserelin) and 12-0-tetradecanoyl phorbol-13-acetate (TPA), and then the LH and LH-beta subunit released into the medium were determined by radioimmunoassay. Buserelin showed its biological activity at a much lower concentration than LH-RH, but both of them caused the release of LH and LH-beta subunit in a dose-dependent manner. Furthermore, intracellular LH synthesis from LH-beta subunit by stimulation with LH-RH or Buserelin was also found. After inducing various degrees of desensitization by stimulation with LH-RH or Buserelin in a dose-dependent manner (the first stimulation), pituitary cells were stimulated with a fixed dose of TPA (the second stimulation) and the released LH was assayed. LH was released almost constantly by the second stimulation, regardless of the dose used for the first stimulation. These results suggest that the C-kinase pathway was unaffected by the desensitization induced with LH-RH or Buserelin.

Animals↗
PubMed1989

Effect of estrogen on the response of thyroid stimulating hormone to substance P in rats.

The role of substance P (SP) in the control of thyroid stimulating hormone (TSH) release and the influence of gonadal steroid were investigated. Intravenous administration of SP failed to alter plasma levels of TSH in ovariectomized (OVX) rats, whereas SP induced a significant increase in plasma TSH in estradiol benzoate-primed (Eb-primed) OVX rats (P less than 0.001). Further, intravenously administered SP did not affect the plasma TSH concentration in normal male rats, but significantly increased it in Eb-primed castrated male rats (P less than 0.01). These data suggest possible roles for SP at the level of the hypothalamus and/or the pituitary gland in stimulating TSH secretion under the influence of estrogen.

Animals↗
PubMed1989

[Galactosyltransferase isozyme II (GT-II) as a new tumor marker for ovarian cancers--especially for clear cell carcinoma].

Serum levels of galactosyltransferase (GT) and its isozyme (GT-II), which transfers galactose from UDP-galactose to N-acetylglucosamine etc., in gynecologic malignancies, were assayed. GT activity was assayed with UDP-[3H] galactose and ovalbumin as substrate, and GT-II was assayed by selectively removing GT-II from serum by immunoabsorption with immobilized monoclonal antibody 3872, followed by assay of bound GT activity. GT was not specific for cancer, but GT-II was positive in 74% of the ovarian cancer patients, and remarkably high serum levels were observed in mesonephroid cancers, indicating its possible usefulness as a new tumor marker. Immunohistochemical staining revealed that GT-II was localized on the cell surface and in the cytoplasm, suggesting its production by tumor cells.

Adenocarcinoma↗
PubMed1989

[Changes in bone mineral content and bone metabolism related to menopause].

Although the phenomenon of postmenopausal osteoporosis has attracted attention, there have been no parameter-matched studies of pre- and postmenopausal difference in metacarpal bone mineral status and bone metabolism. Therefore the authors compared metacarpal bone loss in a group of 41 postmenopausal volunteers (average postmenopausal duration: 39.3 months) and 28 age- and body size-matched controls (age 50-54), using the MD method. Perimenopausal changes in bone metabolism were also examined in these groups. The result revealed that the reduction in the metacarpal bone mineral status due to menopause occurs mainly in the bone mineral density such as GSmin and sigma GS/D. The reduction rate was the highest for the index of GSmin, corresponding to 5.1% per year. Serum levels of Alp and osteocalcin were significantly higher and the U-Ca/cr ratio tended to be higher in the postmenopausal subjects than in controls. The serum levels of calcium regulating hormones such as PTH and calcitonin in these two groups did not differ significantly. However the estrone and the estradiol levels, were significantly lower in postmenopausal subjects. Significant correlations were found between Alp and the postmenopausal period (r = 0.4684), and between the U-Hpr/cr ratio and postmenopausal period (r = -0.5332). It therefore appeared that estradiol is mainly related to postmenopausal bone metabolism causing insufficient suppression of bone resorption. However, calcium regulating hormones appeared to be not directly related to the postmenopausal bone loss mechanism. Bone turnover decreased with the postmenopausal period.

Alkaline Phosphatase↗
PubMed1989

[Assessment of osteopenia following oophorectomy by quantitative computed tomography and its relation with Ca-regulating hormones].

In order to determine the pathogenesis of post-oophorectomy osteopenia, we investigated the bone mineral status and biochemical parameters, and identified high-turnover bone metabolism. The present study was undertaken to determine whether there is a decrease in bone mineral content of peripheral bone or axial bone and cortical bone or trabecular bone using the microdensitometry method and a modified quantitative computed tomography method in 40 [24 premenopausal females (controls) and 16 premenopausal females who underwent oophorectomy]. We also investigated what biochemical and endocrinological parameters are changed, for example, Ca-regulating hormones and sex steroids, etc. As a result, it found that the reduction in bone mineral content due to oophorectomy occurs mainly in the axial bone, especially in the trabecular bone. It was considered that oophorectomy causes high-turnover osteopenia, in which bone formation is promoted but is outweighed by bone resorption, resulting in an overall decrease in bone mineral content. It also seemed that E2 is significantly related to bone metabolism, causing insufficient suppression of bone resorption. However, Ca-regulating hormones appeared not to be directly related to bone metabolism during the period (average: 39.6 months) after oophorectomy.

Absorptiometry, Photon↗
PubMed1989

[The evaluation of CA54/61 in the diagnosis of ovarian cancer--with special reference to the cooperative results of 5 institutes].

The clinical usefulness of a newly developed one-step enzyme-immunoassay, MKS-15, in the diagnosis of ovarian cancer was evaluated with 1,563 serum samples collected at five institutes. In this assay, two monoclonal antibodies, MA54 and MA61, which both recognize the carbohydrate chain in a high molecular weight mucin-type glycoprotein, were used as the immobilized antibody on beads and peroxidase-labeled antibody, respectively. When the cut-off value was set at 20 IU/ml (mean + 3SD), 56% of the sera from ovarian cancer patients were positive, and the positive rates for serous, mucinous, mesonephroid, endometrioid, undifferentiated, and metastatic cancers were 63%, 55%, 52%, 38%, 55%, and 62%, respectively. In sera from patients with benign ovarian tumors, only 4% of the cases were positive, but 7% of benign and low potential malignant cases of mucinous cystadenoma were positive, indicating that CA54/61 cannot distinguish benign mucinous cystadenoma from malignant ones. Since the positive rate for CA125 is rather low in mucinous cyst-adenocarcinoma, CA54/61 may be of clinical value.

Adolescent↗
PubMed1989

[Study on oxytocin secretion from the guinea pig hypothalamo-neurohypophyseal complex (HNC) in organ culture].

To clarify the mechanism of OT secretion of hypothalamus and pituitary origin, in vitro, the guinea pig hypothalamo-neurohypophyseal complex (HNC) was utilized in this study. The HNC, including paraventricular and supraoptic nuclei, was removed and maintained in Eagle's Minimal Essential Medium (pH 7.4) for 7 days at 37 degrees C in a 95% air 5% CO2 environment. The OT content in the hypothalamus and the pituitary remained constant during the period of culture of the HNC. Synthetic OT, hypothalamus or pituitary extracts were eluted separately by ion exchange chromatography and the elution patterns obtained were similar. The stimulation of the HNC with 100mM KCl in the culture caused an increase in OT release. These results suggest that the cultured HNC can be a useful in vitro model for studies of the OT secretion mechanism. After adding several substances to the culture medium, the amount of OT release from the HNC into the culture medium over a 20 minute period, was measured by our own radioimmunoassay. The addition of prostaglandin F2 alpha to the HNC resulted in an increase in OT release while stimulation of D2 or E2 failed to increase. Stimulation of the HNC with vasoactive intestinal polypeptide (VIP) produced an increase in OT release, suggesting the existence of a positive feedback effect of VIP on OT release.

Animals↗
PubMed1989

[Human placental oxytocin and its increase by prostaglandin E2 and F2 alpha].

To investigate the physiological roles of human placental oxytocin (OT)-like substance, partial purification of human placental extract and placental tissue culture were carried out. 1. Both oxytocic immunoreaction in our own specific radioimmunoassay and bioaction on rat uterine contraction were observed in the larger (MW greater than or equal to 5,000) and the smaller molecular part (MW not equal to 1,000) in partially purified placental extracts by gel-filtration using Sephadex G-25. 2. Prostaglandin E2 and F2 alpha enhanced the immunoreactive OT in the cultured human term placental tissue at doses of 1-100 micrograms/ml. These findings are considered to be significant in basic studies of human placental OT-like substance.

Animals↗
PubMed1989

[Analysis of follow-up survey in spinocerebellar degeneration].

Spinocerebellar degeneration (SCD) is associated with other various degeneration of the nervous systems such as the optic tract, pyramidal pathway, extrapyramidal system, nuclei of the brain stem and autonomic nervous system as well as changes of heart. The clinical pattern, also have the great variability. We investigated the mode of progression of clinical symptoms and signs in 214 cases of SCD which were examined 2 times at intervals of about 10 years. 79 of 214 cases were reported to be died at the last examination. 135 alive cases included 3 with the Holmes type, 14 with late cortical cerebellar atrophy (LCCA) 10 with Menzel type, 18 with olive-ponto-cerebellar atrophy (OPCA), 33 with spinocerebellar form (SCF), 6 with Friedreich's ataxia, 18 with hereditary spastic paraparesis (HSP) and 33 with the other type. 79 dead cases included 0 with the Holmes type, 6 with LCCA, 5 with Menzel type, 32 with OPCA, 16 with SCF, 1 with Friedreich's ataxia, 4 with HSP and 15 with the other type. The disability of daily living in SCD revealed slower progression in the advanced stage than in the early stage. Every type of SCD had some different progression of disability each other. In the early stage, Friedreich's ataxia showed the highest progression of disability, but in the advanced stage, Holmes type and the OPCA did. Holmes type showed progression of ataxia without any remarkable change of other systems. LCCA showed increase of abnormality in the eye movements, pyramidal tract and autonomic nervous system in addition to the cerebellar system. OPCA involved multiple systems as ataxia worsening, but Menzel type had no remarkable changes of incidence in eye movement disorder.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Effects of alfacalcidol (1 alpha-OH-D3) on post oophorectomy osteopenia as measured by microdensitometry].

The present study included 24 relatively young patients (48.4 years on average) who had decreased bone mineral levels after oophorectomy (severity scores of 4 or above as judged by the MD method), and the efficacy of active vitamin D3 (D3) was assessed according to the mean percentage of change in MD indices. The patients were randomly divided into two groups of 12 cases each, the D3-treated group and the non-treated group. The D3 treatment was given in the form of 1 microgram/day alfacalcidol for 9.67 months on average. Before and after treatment, the MD indices and serum Al-p, calcium and potassium were measured. The non-treated group was observed for 9.92 months on average, and the same parameters were measured before and after the observation period. There were no significant intergroup differences with regard to age, height, body weight, duration after oophorectomy, severity of decreased bone mineral levels and other background factors. In the treated group, MCI and d tended to increase and to decrease, respectively, GSmin and sigma GS/D also tended to increase and GSmax tended to increase (p less than 0.10). In the non-treated group, MCI decreased and d tended to increase, GSmin and GSmax tended to decrease, and sigma GS/D decreased (p less than 0.05). In the intergroup comparison, GSmax increased in the treated group (p less than 0.05) and sigma GS/D also tended to increase more in the treated group (p less than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗