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Biomedical subjects

M Mizuno

Publications and source records attributed to M Mizuno.

At least 397 records · Page 22Linked to original sources
PubMed1991

Maturational sequence of fetal breathing movements.

The inspiratory times of fetal breathing movements were measured in REM and NREM periods, respectively, and their changes with advancing gestational age were investigated. Ten women without complications in their 20th to 40th week of pregnancy were examined. Fetal breathing movements and REM were observed simultaneously using ultrasonography. REM and NREM periods were selected for analyzing breathing movements separate from the whole examination period. The inspiratory times of fetal breathing movements were measured with the hand-held pressure transducer. The changes in inspiratory time with fetal age showed the same pattern both in REM and NREM periods. There were no significant changes in inspiratory time before 28 weeks gestational age. After that, the inspiratory time lengthened, showing the maximum at 32-35 weeks and then shortened at 36-40 weeks gestational age. There were no differences of the inspiratory time between REM and NREM periods before 32 weeks. After 32 weeks, the inspiratory time in the NREM period was longer than in the REM period. These changes in fetal breathing movements are thought to be caused by the morphological maturation of the fetal lung and the functional development of respiratory and sleep center of the fetal central nervous system.

Embryonic and Fetal Development↗
PubMed1991

Olfactory dysfunction in Parkinson's disease.

An olfactory function test in 18 patients with Parkinson's disease (PD) and 10 age-matched control subjects was performed. Both detection and recognition thresholds were measured with five kinds of synthesized odorants (T & T olfactometry). Before each test, rhinoscopic inspections were performed to exclude subjects who could have respiratory hyposmia. Both detection and recognition thresholds in patients with PD were significantly elevated in comparison with those of control subjects. Auditory acuity of PD patients, however, was well preserved and there was no significant correlation between auditory and olfactory threshold. On the basis of the present study, the authors conclude that olfactory dysfunction is one of the characteristic symptoms of PD and it may be attributed to lesions in the olfactory neural pathway including olfactory neuroepithelium.

Adult↗
PubMed1991

[Pharmacological study on citrus fruits. II. Anti-allergic effect of fruit of Citrus unshiu MARKOVICH (2). On flavonoid components].

A study was carried out to clarify the active component of green fruit of Citrus unshiu MAKOVICH on the type I allergic reaction. The flavonoid component, isolated from its methanolic extract, hesperidin, was found to inhibit histamine release from peritoneal mast cells of rats induced by compound 48/80. Forty eight-hour homologous passive cutaneous anaphylaxis (PCA) in intact rats was significantly inhibited by the oral administration of hesperidin. However, the anti-allergic action on PCA was not observed in adrenalectomized rats. These results suggests that hesperidin is an effective component of the fruit of Citrus unshiu with the anti-allergic action against the type I reaction.

Adrenalectomy↗
PubMed1991

Endothelin-1 and endothelin-3 stimulate prostaglandin E2 secretion from the rat median eminence.

The in vitro effects of endothelin-1 (ET-1) and endothelin-3 (ET-3) on the release of prostaglandin (PG)E2 from the rat median eminence were investigated. The addition of ET-1 from 10(-9) M to 10(-6) M stimulated PGE2 release in a dose-dependent manner (from 10.5 +/- 2.1 to 54.4 +/- 5.6 pg/ME fragment/30 min; mean +/- SEM, p less than 0.001). ET-3 also stimulated the release of PGE2 from 10(-7) M to 10(-5) M dose dependently (from 18.1 +/- 0.7 to 60.9 +/- 17.4 pg/ME fragment/30 min p less than 0.05). The time course effect of ET-3 (10(-6) M) showed that PGE2 release was stimulated within five minutes (control, 1.5 +/- 0.5; ET-3, 15.8 +/- 3.0 pg/ME fragment/5 min, p less than 0.01). These results suggest that ET-1 and ET-3 have some physiological effects on the rat median eminence.

Animals↗
PubMed1991

Stimulatory effect of epidermal growth factor on the development of mouse early embryos in vitro.

Effects of epidermal growth factor (EGF) on the development of mouse 2-cell embryos cultured in vitro were investigated. The addition of EGF at a concentration of 0.5 ng/ml enhanced the development of 2-cell embryos during 24 h of incubation. As expected, EGF stimulated the synthesis of DNA in the 2-cell embryos about 4-fold over the control. The growth-promoting effect of EGF seemed to be specific in that other growth factors, such as transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta (TGF-beta), insulin-like growth factor-1 (IGF-1), platelet-derived growth factor (PDGF), nerve growth factor (NGF) and fibroblast growth factor (FGF) had no effect on the embryonal development. The addition of EGF also increased the rate of RNA synthesis in a dose-related manner between 0.1 and 50 ng/ml. However, protein synthesis was unaffected by EGF. These results raise the possibility that EGF may participate in the process of early embryogenesis in vivo.

Animals↗
PubMed1991

A decline in prolactin levels in amniotic fluid and decidua at term pregnancy after the initiation of labour.

Prolactin is known to inhibit the production of prostaglandins, key substances in the initiation of labour. To explore a possible role of prolactin in human parturition, prolactin levels were therefore measured in amniotic fluid and decidua at full-term pregnancy. Prolactin levels in amniotic fluid before labour were about three times higher than those at labour and they tended to decrease with time during labour. Prolactin levels in decidua before labour were about twice as high as those at labour. These findings suggest a possible involvement of prolactin in human parturition.

Amniotic Fluid↗
PubMed1991

Immunohistochemical studies on the class and the subclass of the anticolon antibody and the distribution of the antigen recognized by the anticolon antibody in patients with ulcerative colitis.

The immunologic mechanisms mediated by anticolon antibodies have been suggested for the injury of colonic mucosa in ulcerative colitis (UC). For the understanding of pathogenetic relevance of the anticolon antibody in UC, we examined the class and the subclass of the anticolon antibody reactive to rat colonic epithelial cells in sera from 10 patients with UC immunohistochemically by an indirect immunoperoxidase method. We also examined the distribution of the antigen recognized by the anticolon antibody by immunoelectron microscopy. The antibody reactive to the rat colonic epithelial cell was detected in 2 of the 10 patients, and the class and subclass of the antibody was mainly IgG2. The antigen recognized by the anticolon antibody was located on the apical membrane of the colonic epithelial cells and mucous substances of the goblet cells. These findings suggest that the anticolon antibody detected in this study is inadequate to cause the colonic mucosal injury by activating complements or mediating antibody-dependent cellular cytotoxicity. A potential pathogenetic role of the anticolon antibody in UC remains to be established.

Adult↗
PubMed1991

Analysis of galactosyltransferase activity in rat gastric mucosa using crude mucosal homogenate.

Mucus glycoprotein is one of the major components of gastric mucus which plays an important role in mucosal defensive mechanisms as a mucus-bicarbonate barrier. Analysis of the mucus glycoprotein synthesis is a useful tool for evaluating gastric mucosal defensive factors. UDP-galactosyltransferase (UDP-Gal-T) is one of the regulating enzymes for the synthesis of the mucus glycoprotein. In the present paper, we studied assay methods for UDP-Gal-T activity in rat gastric mucosa using radiolabeled UDP-galactose and two different kinds of acceptor proteins, namely ovomucoid and asialomucin, and analyzed effects of antisecretory agents on the UDP-Gal-T activity. We used crude supernatants of homogenized scrapings of the fundic part of rat stomach as an enzyme preparation and determined optimal conditions. In each acceptor, Mn2+ and the non-ionic detergent Triton X-100 were required for the enzyme activity. With each acceptor molecule, the type of glycosidic linkages of galactose was beta-type linkage. With asialomucin as an acceptor, UDP-Gal-T activities of rat gastric mucosa decreased after intraperitoneal administration of antisecretory agents, while change of the enzyme activity was not observed with ovomucoid as an acceptor.

Animals↗
PubMed1991

Superinduction of cytotoxic interferon-beta in glioma cells.

The possibility for new interferon therapy was investigated using the effect of endogenous human interferon-beta (HuIFN-beta) on various culture cell lines. Cell lines were exposed to superinduction agents (poly I: poly C, cycloheximide, and actinomycin D) and the production of endogenous interferon analyzed. Quantitative determination of HuIFN-beta and messenger ribonucleic acid (mRNA) showed HuIFN-beta was induced in all of five glioma cell lines, one of two melanoma cell lines, and all of three lung carcinoma cell lines as well as fibroblasts. Northern blot analysis showed HuIFN-beta mRNA induced in glioma cells was identical to that from fibroblasts. Endogenous HuIFN-beta induced from glioma cells had a cytostatic or cytocidal effect against various human glioma cell lines, even those resistant to fibroblast-derived HuIFN-beta. These results show it may be possible to use the induction of excess endogenous cytotoxic HuIFN-beta in human glioma tissue itself.

Fibroblasts↗
PubMed1991

Neuropsychological characteristics of right hemisphere damage: investigation by attention tests, concept formation and change test, and self-evaluation task.

Neuropsychological characteristics of right (non-dominant) hemisphere damage were investigated by attention tests, a concept formation and change test, and a self-evaluation task on a total of 126 brain damaged subjects (66 right hemisphere damaged and 60 left hemisphere damaged). Common response patterns specific to subjects with right hemisphere lesions were studied by three attention tests (audio-motor method, cancellation test, and set dependent activity test). Those with right hemisphere lesions showed a large number of responses (excessive response) and low proportion of correct responses (low hit rate, qualitative deterioration of response), indicating a tendency toward randomness. A concept formation and change test, the new modified Wisconsin Card Sorting Test, was performed to investigate the handling of higher concepts. Only the frequency of difficulty of maintaining set (DMS) was significantly higher in those with right hemisphere lesions. Problems concerning attention and attitude toward the tests, i.e. random attitude were thought to exist in those with right hemisphere damage. Self-evaluation and corrective ability were studied on the self-evaluation task using the audio-motor method. Feedback was less effective in subjects with right hemisphere lesions, and they tended to underestimate their errors. These results were consistent with personality characteristics such as the lack of a serious attitude and poor volition for treatment, which are frequently observed in clinical settings. The above are considered basic, common characteristics of right hemisphere damage. These findings may partially explain the phenomenological characteristics of right hemisphere damage described by various investigators.

Aged↗
PubMed1991

[The changes in cell population and chemical mediators in BALF following local allergen challenge].

In eight subjects who showed dual asthmatic response (DAR) in bronchial provocation tests (BPT) with specific allergens, local allergen challenge (LAC) was conducted using a flexible bronchofiberscope. We examined the concentrations of histamine, leukotriene B4 and C4 (LTB4 and LTC4) and cell populations in bronchoalveolar lavage fluid (BALF) collected before LAC (control), during the immediate response phase (IR), and the late response phase (LR). Control BALF was collected from the left lingula (B4 or B5), and BALF in the IR or LR phase from the right middle lobe (B4 or B5). Each BAL was conducted with 50 ml of saline at 37 degrees C and repeated three times in succession. It was noted that histamine increased significantly (p less than 0.05) in IR-BALF from the control level. In addition, the concentrations of LTC4 and the numbers of eosinophils increased in IR-BALF. In LR-BALF, the numbers of eosinophils (p less than 0.01), and the concentrations of histamine (p less than 0.05), LTC4 (p less than 0.05) and LTB4 increased. From these results, it was suggested that infiltration of eosinophils and various chemical mediators in the bronchial mucosa play important roles in the development of late asthmatic response.

Adolescent↗
PubMed1991

[The changes in plasma beta-thromboglobulin (beta-TG), platelet factor 4 (PF4) and thromboxane B2 (TXB2) after a bronchial provocation test (BPT) with house dust (HD) allergen].

In order to investigate the role of platelets in allergic asthma, the time related changes in plasma levels of beta-TG, PF4 and TXB2 were evaluated following BPT with HD in 19 patients with bronchial asthma who were positive in skin test and RAST to HD. The results obtained were as follows. 1) Plasma beta-TG and PF4 levels tended to increase following BPT with HD at the time of immediate asthmatic response (IAR) in patients showing IAR alone. 2) Plasma beta-TG and PF4 levels increased significantly (p less than 0.05) at IAR and tended to increase at the time of late asthmatic response (LAR) in patients showing a dual asthmatic response (DAR). 3) The levels of plasma TXB2 in patients showing IAR alone significantly increased at IAR (p less than 0.05) and gradually decreased and the levels of plasma TXB2 in patients showing a DAR increased in each period of IAR, 3 hr after BPT and LAR, and the peak of TXB2 was observed in 3 hours after BPT. 4) These results suggest that platelets are activated at IAR and there was also a possible activation in platelets at LAR.

Adult↗