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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 1,081 records · Page 60Linked to original sources
PubMed1991

Concentrations of endothelin-1 in maternal and umbilical cord blood at various stages of pregnancy.

To examine the role of endothelin (ET) in the maternal and fetal circulation, the levels of endothelin-1-like immunoreactivity (ET-1-LI) in the plasma of maternal vein (MV), umbilical vein (UV), and umbilical artery (UA) were determined by a sensitive radioimmunoassay (RIA). Levels of ET-1-LI in MV did not show any significant change (9.9 +/- 1.5 pg/ml, n = 26) throughout normal pregnancy and were similar to those of normal nonpregnant women (10.7 +/- 2.5 pg/ml, n = 5). Levels of ET-1-LI in UV and UA obtained at normal deliveries at term were about three times higher than those in MV. In the patients with mild and severe pre-eclampsia, the levels of plasma ET-1-LI were significantly higher than those of normal pregnancy (14.3 +/- 2.2 pg/ml, n = 5 and 27.2 +/- 8.6 pg/ml, n = 5, respectively). However, in pregnant women with chronic hypertension, the levels of ET-1-LI did not increase when the hypertension did not worsen during pregnancy (11.4 +/- 1.6 pg/ml, n = 7). Moreover, in two pregnant women with abnormally stimulated coagulation, such as acute or subacute DIC, the levels of ET-1-LI were extremely high and returned gradually to those of normal nonpregnant women after the coagulation was normalized by treatment. These results suggest the possibility that ET-1 plays an important role in the pathophysiology of preeclampsia.

Chromatography, Gel↗
PubMed1991

Monocytoid B lymphocytes and epithelioid cell clusters in abscess-forming granulomatous lymphadenitis. With special reference to cat scratch disease.

In order to clarify the appearance of monocytoid B lymphocytes (MBLs) in abscess-forming granulomatous lymphadenitis (AGL) and the relation between AGL and cat-scratch disease (CSD), 48 cases of AGL were studied histologically. MBLs were present in about 50% of AGL cases. Warthin-Starry (WS) silver stain-positive bacteria, which are the causative agent of CSD, were present in 52.4% of AGL cases with MBLs and 59.2% of AGL cases without MBLs. The appearance of MBLs in AGL was not related to various clinical features, including disease interval from initial lymphadenopathy to lymph node biopsy. Histologically, epithelioid cell clusters appeared in about 70% of MBL-positive AGL cases, but were not observed in MBL-negative AGL. Therefore, a close interaction between MBLs and epithelioid cells in AGL is suggested, and we emphasize that the histological features of some AGL cases resemble those of toxoplasmic lymphadenitis.

Abscess↗
PubMed1991

Contraction of rat thoracic aorta strips by endothelin-1 in the absence of extracellular Ca2+.

1. Endothelin-1 (ET-1) caused a concentration-dependent contraction of helical strips from rat thoracic aorta in the absence of extracellular Ca2+. The Ca(2+)-depleted muscle strips, prepared by three repeated applications of 10(-2) M caffeine or 10(-6) M noradrenaline in Ca(2+)-free buffer, were contracted by 10(-8) M ET-1 in the same manner as non-treated strips. 2. In the absence of extracellular Ca2+, 10(-7) M phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, induced a small but sustained contraction of the rat thoracic aorta strips within 60 min. Preincubation of the strips with 10(-7) M PMA for 60 min in Ca(2+)-free buffer, did not affect the 10(-8) M ET-1-induced contraction, but decreased the 5 x 10(-8) M phorbol 12,13-dibutyrate (PDB)-, or the 10(-7) M PMA-induced contraction, and potentiated the contraction induced by 10(-8) M urotensin II. Preincubation with 10(-8) M ET-1 (which induced maximum contraction) for 25 min in Ca(2+)-free buffer did not change the subsequent contraction induced by PMA (10(-7) M) or urotensin II (10(-8) M) but gave a somewhat lower maximum tension than in non-treated strips. 3. Calyculin-A, a potent inhibitor of phosphatase, also induced a contraction of the Ca(2+)-depleted muscle strips in Ca(2+)-free buffer. Preincubation of the strips with ET-1 (10(-8) M) or PMA (10(-7) M) decreased the calyculin-A (3 x 10(-8) M)-induced contraction.4. These results suggest that ET-1 may induce phosphorylation of an unknown protein either without an increase in myoplasmic Ca2 + concentration or, alternatively, with mobilization of intracellular Ca2+ from noradrenaline- and caffeine-insensitive Ca2 + sources, through a mechanism different from that of phorbol ester.

Animals↗
PubMed1991

Ultrastructural localization of type IV collagen and laminin in the Disse space of rat liver with carbon tetrachloride induced fibrosis.

Monospecific antibodies, directed against type IV collagen and laminin, were used to clarify the process of sinusoidal capillarization in rats after carbon tetrachloride (CCl4) intoxication by the direct immunoperoxidase method. After acute intoxication, both type IV collagen and laminin were increased in the area of hepatic necrosis, adjacent to the central veins; however, sinusoidal capillarization was not found. During chronic intoxication, deposition of laminin was co-distributed with that of type IV collagen, but deposition proceeded more slowly than that of the type IV collagen. Deposition of laminin was increased in the Disse space. Sinusoidal capillarization was noted as thick deposition of both antigens by light microscopy. Immunoelectron microscopy showed that both components were continuously present in the Disse space. Intracellularly, both antigens were found in the rough endoplasmic reticulum (RER) of fat-storing cells (FSC) and endothelial cells, and these cells showed morphological changes, becoming slender and flattened. In contrast, few immunoreactive products of the two components were observed in the hepatocytes. These findings suggest that type IV collagen and laminin are indispensable for the establishment of sinusoidal capillarization, and that FSC play an important role in the production of both components.

Animals↗
PubMed1991

Atrial natriuretic peptide in acute hypoxia-induced pulmonary hypertension in rats.

To test the hypothesis that exogenous atrial natriuretic peptide (ANP) prevents the acute pulmonary pressor response to hypoxia, ANP (20-micrograms/kg bolus followed by 1-microgram.kg-1.min-1 infusion) or vehicle was administered intravenously to conscious rats beginning 3 min before exposure to hypoxia or room air for 90 min. Exogenous ANP abolished the acute pulmonary pressor response to hypoxia in association with marked and parallel increases in plasma ANP and guanosine 5'-cyclic monophosphate (cGMP) and with a significant increase in lung cGMP content. To examine whether endogenous ANP modulates the acute pulmonary pressor response to hypoxia, rats were pretreated with a monoclonal antibody (Ab) to ANP and exposed to hypoxia. Mean pulmonary arterial pressure (MPAP) in the Ab-treated rats was not different from control over the first 6 h of hypoxic exposure. Thereafter, the Ab-treated group had significantly higher MPAP than control. Our data suggest that 1) exogenous ANP blocks the pulmonary pressor response to acute hypoxia via stimulation of cGMP accumulation in the pulmonary vasculature, and 2) endogenous ANP may modulate the subacute, but not acute, phase of hypoxic pulmonary hypertension.

Acute Disease↗
PubMed1991

Manometric and histologic assessment following proctocolectomy and straight enteroanal anastomosis in canines.

Serial manometric studies were performed in mongrel dogs before and after total colectomy, mucosal proctectomy and interposed jejunoanal anastomosis without pouch. Fecal continence and body weight gain were clinically satisfactory by 28 weeks after surgery. Even at 28 weeks after the mucosal proctectomy, the mean maximal resting anal sphincter pressure was significantly lower than the preoperative level (p less than 0.001). Neorectal compliance also decreased. The rectoanal inhibitory reflexes were not observed 2 weeks after the mucosal proctectomy but atypical to typical patterns gradually appeared up to 28 weeks following the mucosal proctectomy. Histologic examination showed no injury of anal sphincter muscles. Mild inflammation was found in the neorectal mucosal layer in all animals. Meissner's plexus in rectal muscular cuff was almost completely disrupted. These data suggested that there is certain limitation in restoration of anoneorectal function after mucosal protectomy and enteroanal anastomosis, though with gentle and careful operations.

Anal Canal↗
PubMed1991

Light and electron microscopic localization of brain natriuretic peptide in relation to atrial natriuretic peptide in porcine atrium. Immunohistocytochemical study using specific monoclonal antibodies.

BACKGROUND: Although first isolated from the porcine brain, brain natriuretic peptide (BNP) is also found in the heart, particularly in the atria. METHODS AND RESULTS: We examined the immunocytochemical localization of BNP in relation to atrial natriuretic peptide (ANP) in five porcine atria using highly specific monoclonal antibodies. With the use of an indirect immunoperoxidase method, serial sections examined by light microscopy showed foci of multihormonal myocytes containing both ANP and BNP localized in the subendocardium. Monohormonal myocytes containing ANP only were observed in the subepicardium and part of the subendocardium. The staining intensity of ANP and BNP showed a transmural gradient from the subendocardium to the subepicardium. At the electron microscopic level, double immunocytochemistry using a two-face immunogold-staining method revealed two types of granules: Type 1 is a monohormonal granule containing ANP alone, and type 2 is a multihormonal granule containing both ANP and BNP. Although most atrial myocytes contained both, type 1 granules were frequently observed in the epicardial side, and type 2 granules were frequently observed in the endocardial side. We observed a few type 2 granules even in the light microscopically monohormonal myocytes. CONCLUSIONS: These data suggest that the atrial myocyte population comprises single, multipotential cells able to synthesize both natriuretic peptides in varying proportions. The atrial transmural gradient of BNP and ANP may be related to responses to wall stress.

Animals↗
PubMed1991

The involvement of platelet-activating factor in thrombocytopenia and follicular rupture during gonadotropin-induced superovulation in immature rats.

To investigate whether the platelets in the ovaries are activated by the action of platelet-activating factor (PAF) during gonadotropin-induced ovulation, we examined the changes in the platelet count in immature rats after administration of PMSG followed 48 h later by human CG (hCG). The platelet count in the inferior vena cava was significantly decreased 48 h after PMSG administration and was further decreased after hCG administration. When both ovaries of rats were extirpated, the administration of PMSG and hCG did not decrease the platelet count. Subcutaneous administration of a PAF antagonist, Y24180 (0.5-5 mg/kg.6 h), after PMSG injection decreased the number of ova shed in a dose-dependent manner. The decrease in the platelet count induced by the administration of PMSG and hCG was reversed to the level of the untreated control group by Y24180 (2.5 mg/kg.6 h). This inhibitory activity of Y24180 on ovulation and thrombocytopenia was completely reversed by the ip injection of synthetic PAF. Subcutaneous administration of indomethacin (IDM) also reduced the number of ova shed in a dose-dependent manner. However, thrombocytopenia was not reversed by IDM. Moreover, the inhibition of ovulation by IDM was not reversed by synthetic PAF. The present study suggests that: 1) platelets are activated by PAF during gonadotropin-induced ovulation in immature rats; 2) PAF is also involved in the rupture of follicles; 3) the presence of the ovary is indispensable for the generation of PAF in gonadotropin-stimulated immature rats; and 4) the mechanism of PAF action on ovulation may be different from that of prostaglandins.

Animals↗
PubMed1991

New hydroxyl protecting groups of a safety-catch type removable by reductive acidolysis.

New hydroxyl protecting groups of a safety-catch type, i.e., 4-methylsulfinylbenzyl-oxycarbonyl (Msz) group for Tyr and 4-methylsulfinylbenzyl (Msob) ether for Thr, have been developed. O-Msz and O-Msob groups are stable under both acidic and basic conditions and can be removed by a one-pot reaction involving reductive acidolysis using tetrachlorosilane-trifluoroacetic acid (TFA)-scavengers. Using these new protecting groups, a 17 residue-peptide, gamma-endorphin, was successfully synthesized by the efficient solid phase method.

Amino Acid Sequence↗
PubMed1991

Quantitative lymphoscintigraphy using 99Tcm human serum albumin in patients with previously treated uterine cancer.

To evaluate the clinical usefulness of lymphoscintigraphy using 99Tcm human serum albumin (99Tc-HSA) in assessing lymphoedema in the lower extremities, lymphoscintigraphy was performed by subcutaneous injection of 7.4 MBq of 99Tcm-HSA in 26 patients with uterine cancer, previously treated by operation (OP) and/or radiation therapy (RT), and in five controls. Radioactivity at the injection site in the lower extremities was counted for 3 min at 10 min (A) and at 3 h (B) after injection, and clearance of 99Tcm-HSA was defined as (1-(B)/(A)) x 100(%). Clearance in controls was 46.8 +/- 3.9%, which was significantly more than those in the other treatment groups. Clearances in patients treated with both OP and RT were less than those in patients treated with either OP or RT alone (30.1 +/- 11.4 vs. 41.9 +/- 8.9, 43.7 +/- 9.6%, respectively; p less than 0.01). The clearance in legs with lymphoedema was less than those without lymphoedema in patients treated with both OP and RT (16.6 +/- 7.7 vs. 34.9 +/- 9.3%; p less than 0.01) and in patients treated with RT (33.1 +/- 7.4 vs. 48.0 +/- 5.6%; p less than 0.01). There was a significant difference between clearance in controls and clearance in non-oedematous patients' legs treated with OP and RT (p less than 0.01). In patients treated with RT alone, radiation dose was closely correlated with 99Tcm-HSA clearance and with the development of lymphoedema. These data suggest that lymphoscintigraphy using 99Tcm-HSA is useful in evaluating lymphoedema and that radiation dose is one of the factors in the development of lymphoedema.

Adult↗
PubMed1991

Epidemiological and pathological studies on congenital diffuse hyperplastic goiter in calves.

Perinatal diseases such as weak calf, stillbirth, or abortion were found in 86 calves from about 600 cows in a farm (A Farm) in 1987 and 1988. Such perinatal diseases were decreased to 36 calves in 1989 and 1990 after an additional supply of seaweed was made to the maternal feeds. From these cases, 23 stillborn and weak calves were pathologically examined. The mean weight with standard deviation of the 18 thyroid glands was 36.3 +/- 28.6 g before feeding of the seaweed supplement, and 12 (67%) of the glands showed moderate to marked degree of diffuse hyperplastic goiter in histological criteria. On the other hand, 5 glands weighed 12.0 +/- 3.4 g and revealed no such histological lesions after the additional supply. These results suggest that the goiter had been associated with birth of weak calves. Further study was performed on 37 newborn calves affected with Akabane disease in 1986 in A Farm and the neighbouring B Farm located. Seven (54%) of 13 thyroid glands from A Farm and 1 (4%) of 24 glands from B Farm showed histologically moderate to marked goitrous lesions. There were dotted "Inugarashi", Rorippa indica, family Cruciferae in both pastures. The mean iodine contents of the orchard grasses were 87 and 121 micrograms/kg on dry basis in A and B Farms. Marginal deficiency or lower limit of iodine and possible thiocyanate content of "Inugarashi" may have been responsible for the goiter in the farms.

Abortion, Veterinary↗
PubMed1991

Enhanced norepinephrine release in hypothalamus from locus coeruleus in SHR.

The hypothesis that a functional projection from the locus coeruleus (LC) to the posterior hypothalamus contributes to the development of hypertension in SHR, was tested by measuring norepinephrine (NE) in the posterior hypothalamus by brain dialysis after injections of L-glutamate (L-glu) into LC. L-glu elicited a prolonged elevation of blood pressure in both SHR and WKY. Pressor effects were significantly larger in SHR than in WKY. Extracellular NE in the posterior hypothalamus increased after LC stimulation; NE release was significantly higher in SHR than in WKY. Injections of 6-hydroxydopamine (6-OHDA) into posterior hypothalamus lowered the resting blood pressure and attenuated the pressor responses to L-glu injections into the LC in SHR. These findings suggest that the LC projects functionally to the posterior hypothalamus and that the projection can contribute to the development of hypertension in SHR.

Animals↗
PubMed1991

[Superoxide dismutase (SOD) activity measured by ESR-spin trapping method in canine vocal cords].

Recently, superoxide dismutase (SOD) has been regarded as a scavenger of superoxide radical which is a important factor of 'reperfusion injury' in ischemic heart or in brain disorder. Its low activity means cell susceptibility to the superoxide radical in tissues. The SOD activity was examined in ten canine larynges after phonation by a electron spin resonance (ESR)-spin-trapping method. The values of mean SOD activity at the middle part of the membranous vocal cord, the vocal process of the arytenoid and the subglottal portion were 67.84 +/- 11.06 U/ml/g, 121.94 +/- 19.46U/ml/g and 115.46 +/- 19.18U/ml/g, respectively. There was a significant difference between the value of the membranous vocal cord and those of the other two (P less than 0.01). The result suggests that the low SOD activity at the part of the membranous vocal cord might relate to a pathogenesis of the laryngeal polyp and vocal nodule. The reperfusion injury may participate in the cause of such vocal cord disorders which grow commonly at the middle part of the membranous vocal cord.

Animals↗
PubMed1991

[Study on eosinophil cationic protein (ECP) and arylsulfatase B in nasal secretions and sera from patients with nasal allergy].

Recently four tissue toxic proteins namely major basic protein (MBP), eosinophil peroxidase (EPO), eosinophil-derived neurotoxin (EDN), and eosinophil cationic protein (ECP) were found in eosinophilic leucocytes. Although the characteristics of these proteins concerning tissue damage in the local site of type I allergic reaction have been investigated mainly in lower respiratory tract, the actual clinico-pathological roles of these proteins in nasal allergy are not clarified. Contrary, eosinophils also have histaminase, arylsulfatase, phospholipase D, which are considered to act on a negative feedback mechanism in allergic reaction through inactivation of chemical mediators. Therefore, estimation of ECP and simultaneously arylsulfatase B in nasal secretion and the sera from patients with nasal allergy may clarify the dynamics of clinico-pathological state, especially in the late phase of allergic reaction in each patients. ECP concentrations in the nasal secretions from 22 patients and in the sera from 12 patients with nasal allergy were measured by RIA method. The activities of arylsulfatase B in the nasal secretions and the sera were also estimated in the same specimens as ECP by measuring its hydrolytic activity using p-nitro cathecol sulfate as a substrate. The results obtained were as follows; 1) There was a significant correlation between ECP concentrations in the nasal secretions and the severities of clinical symptoms, especially the degree of nasal obstruction. ECP concentrations also significantly correlated to the score of eosinophilic leucocytes in the nasal smears. 2) The serum ECP concentrations significantly correlated to the number of eosinophilic leucocytes in the peripheral blood, and also showed slight tendency of correlation to the severity of clinical symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Proteins↗
PubMed1991

[Two case reports of eosinophilic cystitis--clinical review of 43 cases in Japan].

Two cases of eosinophilic cystitis are reported. Case 1 was a 7-year-old boy with pollakisuria and case 2 was a 20-year-old man with right lower abdominal pain. They were suspected of bladder sarcoma after the examinations by cystoscopy, IVP, ultrasonography, CT and NMR-CT. Transurethral, percutaneous and open biopsies were performed and histological examination revealed massive infiltration of eosinophils mainly in the vesical muscle layer without malignant cells. We could establish the diagnosis only by biopsy. In case 1, IgE RAST was positive for tick and case 2 seemed to be allergic to rare beef. We presumed that they caused eosinophilic cystitis.

Adult↗