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R Iizuka

Publications and source records attributed to R Iizuka.

At least 37 records · Page 2Linked to original sources
PubMed1991

Loss of dendritic synapses in the medial amygdala associated with kindling.

Kindling stimulation was given in the basolateral amygdala (BLA), the septal area or the corpus callosum in the right hemisphere of adult rats. The density of dendritic synapses was electron microscopically studied in the medial amygdaloid nucleus (MAN) ipsi- and contralateral to the stimulation side. The number of dendritic synapses was markedly decreased in both sides of the MAN of 3 groups of kindled rats. Such reduction occurred in both dendritic shaft and spine synapses. The most remarkable decrease was obtained in the BLA kindling. These results suggest that a decrease of synapses may provide a morphological basis for kindling.

Amygdala↗
PubMed1991

Parvalbumin-immunoreactive neurons in the cortex in Pick's disease.

Parvalbumin (a calcium-binding protein)-immunoreactive (PV-Ir) neurons in the cerebral cortex were examined in 20 postmortem brains obtained from elderly controls and patients with Pick's disease (PD). The type of PV-Ir neurons and their distribution in control and PD brains were similar. The number of PV-Ir neurons in PD brains did not differ significantly from that in the control brains either. These findings suggested that PV-Ir neurons in the cortex are not affected in PD brains. A significant loss of PV-Ir neurons has already been reported in brains obtained from patients with Alzheimer-type dementia (ATD), and the present results suggest the possibility that the damage of PV-Ir neurons might be comparatively selective for ATD brains.

Aged↗
PubMed1991

A study on postmortem stability of vasopressin messenger RNA in rat brain compared with those in total RNA and ribosomal RNA.

Postmortem stability of arginine-vasopressin (AVP) messenger RNA (mRNA) in the rat brain was studied comparing changes with those in the recovered amounts of total RNA and ribosomal RNA (rRNA). The amount of AVP mRNA and rRNA showed a decrease with increasing time interval after death (postmortem time), whereas the amount of total RNA did not alter with postmortem time. The half-life of AVP mRNA in the rat postmortem seemed to be approximately 16 hrs. The analysis of the ratio of AVP mRNA to 18S-rRNA suggested that AVP mRNA was degraded postmortem more rapidly than rRNA. These results suggest that autopsied human brains should be used for AVP mRNA study within a short postmortem time.

Animals↗
PubMed1991

Age- and sex-related differences in the nerve growth factor distribution in the rat brain.

Levels of the nerve growth factor (NGF) have been measured in various brain regions of young and aged male and female rats of Wistar strain by means of a highly sensitive two-site enzyme immunoassay system for beta-NGF. Among the ten regions examined, the amount of NGF per wet weight of tissue was found to be highest in the hippocampus, irrespective of the sex and age. The NGF concentration in the hippocampus of female rats at 3 months of age was comparable to that of same aged males. Further, there was no significant difference in the NGF levels of the hippocampus between young and age males. However, the NGF level was significantly lower in aged females as compared to that in 3- or 4-month-old females, and hence the marked male-female difference was found in the NGF levels in aged Wistar rats.

Aging↗
PubMed1991

A possible mechanism of immunotherapy for patients with recurrent spontaneous abortions.

The mechanism of the beneficial effect of immunotherapy for human reproductive wastage remains to be elucidated. Induction of blocking antibodies such as anti-HLA class II antibodies and anti-idiotypic antibodies was investigated as the mechanism of specific immunosuppression in pregnancy. We reported the changes in the mixed lymphocyte reaction (MLR), T-cell subsets, and generation of anti-idiotypic antibodies after immunotherapy compared to before immunotherapy. MLR was significantly (P less than 0.001) inhibited after the immunization. The mean inhibition rate was 50.2%, suggesting that MLR blocking antibodies were induced by immunotherapy. Binding of autoantibodies to alloactivated maternal lymphoblasts against the paternal lymphocytes was detected in postimmunization cases in two-color flow-cytometric experiments. This suggests that anti-idiotypic antibodies were induced by the immunotherapy. The percentage of cytotoxic T-cells was significantly decreased (P less than 0.05) and the percentage of suppressor T-cells was significantly increased (P less than 0.01) after the immunotherapy, suggesting that a cell-mediated immune response was induced by the immunotherapy.

Abortion, Habitual↗
PubMed1991

Current comprehensive therapy of habitual abortion.

Habitual abortion is sometimes an incurable pathogenetic state. Even more serious to both the patient and gynecologist is that the incidence of repeated reproductive wastage is higher in subsequent pregnancies. We registered more than 1,000 women with repeated spontaneous abortions in this clinic for 5 years and analyzed their pathogenesis for the wastages by several different approaches. One hundred twenty-four women were diagnosed as having a congenital uterine abnormality. Metroplasty was performed in 50 patients, resulting in 82% successful subsequent pregnancies, whereas more than 98% of the pregnancies had terminated in spontaneous abortion before the operation. By measuring anticardiolipin antibody (ACA) and lupus anticoagulant (LA), the present study diagnosed several cases as antiphospholipid syndrome, and successfully pregnant patients were observed and treated with appropriate medications. Fifty-five partners of 54 couples had either a chromosomal abnormality or normal variants, showing a high incidence of spontaneous abortion in each type of abnormality. In the other 311 cases, female partners were treated by the immunotherapy of the husbands' lymphocytes in pre- and postgestational periods. Among them, 200 women became pregnant, and 147 cases successfully maintained the pregnancy. These studies indicate that early diagnosis through comprehensive examinations is essential for effective treatment of curable fetal loss in human reproduction.

Abortion, Habitual↗
PubMed1991

New pathologic observations in juvenile onset parkinsonism with dystonia.

A patient with hereditary juvenile onset parkinsonism with dystonia died at age 39. There were Lewy bodies and regionally selective neuronal damage in the substantia nigra pars compacta. These changes closely resemble those seen in Parkinson's disease, and emphasize the selective vulnerability of the ventral tier of the pars compacta in these degenerations.

Adult↗
PubMed1991

A disorganized increase of galanin-like immunoreactivity in cerebral cortex of Alzheimer-type dementia brains.

Galanin (GAL), a neuropeptide which has been reported to inhibit the evoked release of acetylcholine, is widely distributed in the mammalian central nervous system. In the present study, GAL-like immunoreactivity (LI) was measured in the cerebral cortex of autopsy brains of patients with the Alzheimer-type dementia and controls using an enzyme immunoassay technique. GAL-LI tended to be increased in the ATD brains and the difference was statistically significant in the frontal cortex. Moreover, although significant correlations of GAL-LI between regions of the cerebral cortex were found in the control brains, no such correlations were found in the ATD brains. These findings suggest a disorganized increase in GAL-LI in the cortex of ATD brains.

Alzheimer Disease↗
PubMed1991

[Statistical analysis of possible causes of repeated spontaneous abortions].

The possible causes of early pregnancy failure in one thousand, three hundred and seventeen women (n = 1,317) with a history of repeated reproductive wastage were analysed and the results of treatment for each etiology were evaluated. Out of 1,200 hysterosalpingographies, 188 (15.7%) congenital uterine anomalies were detected and the degree of each uterine cavity deformity was evaluated by the X/M ratio. Metroplasty was performed on 71 women with no other causes of spontaneous abortion, and more than 84% of the post-operative pregnancy were successfully maintained. One hundred and four (n = 104, 5.5%) out of 949 couples with a high incidence of reproductive failure had either a chromosomal abnormality or normal variants in the wife and/or husband. Twelve cases (n = 12, 8.1%) had a positive analysis for anticardiolipin antibody among 148 women examined. Immunotherapy utilizing the husband's lymphocytes was indicated for four hundred and seventy three (n = 473) other couples with no other abnormalities likely to induce spontaneous abortions. This treatment brought approximately 80% of pregnancies to successful termination and 199 deliveries were recorded with this immunotherapy. The present study suggests that the causes of early pregnancy failure are complex, but that most of the causes of repetitive wastage are curable after exact diagnosis and appropriate treatment.

Abortion, Habitual↗
PubMed1991

[Maternal immune responses induced by the immunotherapy in patients with recurrent spontaneous abortions].

The mechanism of the beneficial effect of immunotherapy for human reproductive wastage remains to be elucidated. The induction of blocking antibodies such as anti-HLA class II antibodies and anti-idiotypic antibodies was investigated as the mechanism of specific immunosuppression in pregnancy. We reported that changes in a mixed lymphocyte culture (MLC), T-cell subsets and generation of anti-idiotypic antibodies after immunotherapy compared to before. MLC was significantly (p less than 0.001) inhibited after the immunization. The mean inhibition rate was 50.5%, suggesting that MLR blocking antibodies were induced by immunotherapy. We demonstrated that this blocking effect was specific to the husband, because the inhibition of one-way MLC reactions which were set up with responding maternal lymphocytes and MMC-treated stimulating lymphocytes of third parties were significantly low (p less than 0.05) compared to stimulation with paternal lymphocytes. The binding of autoantibodies to alloactivated maternal lymphoblasts against the paternal lymphocytes was detected in post-immunization cases in two-color flow-cytometric experiments. This strongly suggests that anti-idiotypic antibodies were induced by the immunotherapy. The percentage of cytotoxic T cells was significantly decreased (p less than 0.05) and the percentage of suppressor T cells was significantly increased (p less than 0.01) after the immunotherapy, suggesting that a cell-mediated immune response was induced by the immunotherapy.

Abortion, Habitual↗
PubMed1990

Cell membrane changes in brains manifesting senile plaques: an immunohistochemical study of GM1 membranous ganglioside.

To investigate structural changes in cell membranes of the Alzheimer-type dementia (ATD) brain, we immunostained for GM1 ganglioside which is a major component of the cell membrane. Our results have shown that astrocytic membranes and senile plaques (SPs) have the same immunoreactivity against the monoclonal anti-ganglioside GM1 antibody. Moreover, the astrocytic processes within the SPs were altered and their abnormal membranes seemed to contribute to the formation of SPs.

Aged↗
PubMed1990

Cancer-associated galactosyltransferase as a new tumor marker for ovarian clear cell carcinoma.

Serum cancer-associated galactosyltransferase antigen (caGT) was assayed in gynecological cancer patients by means of a GT-II-reactive monoclonal antibody (MAb 3872)-based immunoassay. Thirty-six of 47 (75%) ovarian cancer patients showed a significant elevation of caGT in serum above the cutoff level of 200 milliunits/ml (mean +/- 2 SD) determined from normal controls. Particularly, serum caGT levels in eight of nine patients with ovarian clear cell carcinoma were above the cutoff value, and six of them gave more than 200 milliunits/ml. Elevation of caGT in serum from pregnant women was also detected, and the level increased during the course of gestation. Immunohistochemical study revealed that not only various ovarian carcinoma cells in vivo and in vitro, but also syncytiotrophoblast of early gestational placenta, fetal tissues such as mucus-producing cells in the lower alimentary tract, and renal tubules at the 11th week of gestation were stained with MAb 3872, thus indicating its oncofetal character. Compared with CA-125, caGT showed a lower false-positive rate (10%) in benign gynecological diseases, and there was no correlation between caGT and CA-125 values. Therefore, caGT will be a useful tumor marker for ovarian cancers, especially for clear cell carcinoma.

Adenocarcinoma↗
PubMed1990

Measurement of serum unconjugated estriol and estradiol by high-performance liquid chromatography.

Measurement of Estriol (E3) and estradiol (E2) within 22 min by high-performance liquid chromatography (HPLC) was achieved in this study, and the values were compared with those of a radioimmunoassay (RIA). A totally computerized HPLC method was developed for measuring unconjugated E3 (u-E3) and E2 (u-E2) in the sera of pregnant women. The serum samples were injected directly into the apparatus and transferred to a pretreatment column where the estrogens were absorbed while hydrophilic components such as proteins and carbohydrates were excluded. The estrogens were then passed through another separation column containing a new type of polymer gel. The mobile phase consisted of an acetonitrile-water mixture, and separation was achieved by means of a reversed-phase procedure. The eluate was monitored for fluorescence. All procedures were monitored and controlled with a built-in microcomputer. Serum samples from 97 normal pregnant women at 20-41 wk gestation were simultaneously assayed by HPLC and RIA. The correlations obtained by HPLC and RIA were as follows: u-E3, y = 0.905x - 0.385, with a coefficient of correlation of r = 0.912; for u-E2, y = 0.964x + 5.024, with a coefficient of correlation of r = 0.841 (y, RIA value; x, HPLC value). The quick measurement of u-E3 and u-E2 by HPLC can be a useful method for evaluating fetoplacental function.

Chromatography, High Pressure Liquid↗
PubMed1990

Full physiological maturation in vitro of immature mouse oocytes induced by sequential treatment with follicle-stimulating hormone and luteinizing hormone.

Cumulus cell-enclosed immature mouse oocytes were matured in medium supplemented with various combinations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol. FSH or LH alone stimulated oocyte maturation, resulting in a significant increase in the rate of development to blastocysts following fertilization in vitro and embryo culture. There was no significant difference between FSH and LH. The effect of FSH was neutralized by FSH antiserum, while that of LH was not, indicating that the stimulation of maturation by LH was not due to FSH contamination in the LH preparation. When LH was added after 2 hr of culture with FSH (sequential combination), blastocyst development was significantly increased compared with FSH alone, reaching the same level as the in vivo matured oocytes. The addition of estradiol, 0.1 ng/ml, to the sequential combination of FSH and LH had no effect, while 0.01 and 1 ng/ml produced a negative effect. The birth rate of normal live offspring following embryo transfer showed no significant difference between embryos derived from oocytes matured in vivo and in vitro (sequential combination with or without 0.1 ng/ml estradiol) or between the two in vitro treatment groups.

Animals↗