Search PubMed⌕ Search

Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 1,063 records · Page 59Linked to original sources
PubMed1991

[Detection of common bile duct stones by hepatobiliary scintigraphy].

Hepatobiliary scintigraphy and direct X-ray cholangiography were compared in 29 patients with common bile duct (CBD) stones confirmed at surgery. The scintigraphic findings included no visualization of the biliary system (NV), pooling of bile in the biliary system (PB), prolonged transit time over 60 min (PTT), filling defect in the CBD image (FD), and reflux of bile toward the intrahepatic ducts after gallbladder stimulation (RB). The positive rates of NV, PB, PTT, FD, and RB in patients with CBD stones were 7%, 31%, 17%, 48%, and 14%, respectively. One or more of these five findings was found in 83%. Although the NV was a useful finding suggesting complete obstruction of the CBD, it shared little in the diagnosis of CBD stone. The positive rate of the PB was relatively high and it would be a useful finding as an indication of the presence of passage disturbance of the CBD. The PB was usually accompanied by the FD. The PTT had some usefulness in the detection of incomplete obstruction of the CBD in patients with a visualized gallbladder. In patients with no visualization of the gallbladder, however, the transit time tended to be shorter than that of gallbladder visualized patients. Therefore, the judgment of PTT in patients with no visualized gallbladder needed another criteria. The FD was the most frequent among the five findings and the sites of FD correlated well with CBD stones on direct X-ray cholangiography. The FD would be a reliable finding indicating CBD stone or CBD stenosis. Although the RB was a finding limited in patients with a visualized gallbladder, it seemed to be a helpful findings for the detection of CBD stone in patients with a mildly dilated CBD.

Adult↗
PubMed1991

Ammonia and lactate in the blood after short-term sprint exercise.

Nine well-trained subjects performed 15-, 30- and 45-s bouts of sprint exercise using a cycle ergometer. There was a significant difference in the mean power between a 15-s sprint (706.0 W, SD 32.5) and a 30-s sprint (627.0 W, SD 27.8; P less than 0.01). The mean power of the 30-s sprint was higher than that of the 45-s sprint (554.7 W, SD 29.8; P less than 0.01). Blood ammonia and lactate were measured at rest, immediately after warming-up, and 2.5, 5, 7.5, 10, 12.5 min after each sprint. The peak blood ammonia content was 133.8 mumol.l-1, SD 33.5, for the 15-s sprint, 130.2 mumol.l-1, SD 44.9, for the 30-s sprint, and 120.8 mumol.l-1, SD 24.6, for the 45-s sprint. Peak blood lactates after the 15-, 30- and 45-s sprints were 8.1 mmol.l-1, SD 1.7, 11.2 mmol.l-1, SD 2.4, and 14.7 mmol.l-1, SD 2.1, respectively. There was a significant linear relationship between peak blood ammonia and lactate in the 15-s (r, 0.709; P less than 0.05), 30-s (r, 0.797; P less than 0.05) and 45-s (r, 0.696; P less than 0.05) sprints. Though the peak blood lactate content increased significantly with increasing duration of the sprints (P less than 0.01), no significant difference was found in peak blood ammonia content among the 15-, 30- and 45-s sprints. These results suggest that the peak value of ammonia in the blood appears in sprints within 15-s and that the blood ammonia level is linked to the lactate in the blood.

Adolescent↗
PubMed1991

Effect of trans fatty acids on plasma lipids, platelet function and systolic blood pressure in stroke-prone spontaneously hypertensive rats.

To investigate the effect of trans fatty acids on plasma lipid levels and systolic blood pressure, hydrogenated corn oil was fed to SHRSP (stroke-prone spontaneously hypertensive rats) and WKY (Wistar-Kyoto) rats for 30 days. Significantly lower systolic blood pressure and plasma total cholesterol were observed in SHRSP rats fed trans fatty acids when compared with rats fed cis fatty acids from olive oil. In addition, higher HDL cholesterol and lower VLDL plus chylomicron cholesterol levels were found in SHRSP rats fed trans fatty acids. Although no significant changes of systolic blood pressure and plasma total cholesterol levels were observed in WKY rats after trans fatty acids treatment, WKY rats fed trans fatty acids had lower plasma LDL cholesterol and higher HDL cholesterol levels. In addition, platelet aggregation induced by collagen was decreased in WKY rats fed trans fatty acids. It is interesting that trans fatty acids increased the activity of plasma lecithin:cholesterol acyltransferase (LCAT) in both SHRSP and WKY rats. The observed influence of trans fatty acids on plasma lipid levels, systolic blood pressure and platelet aggregation suggests that trans fatty acids might prevent thrombotic disorders in SHRSP rats.

Animals↗
PubMed1991

Effect of alpha-adrenergic blockade on blood pressure, glucose, and lipid metabolism in hypertensive patients with non-insulin-dependent diabetes mellitus.

To clarify the long-term effects of alpha-adrenergic blockade on blood pressure, glucose, and lipid metabolism, a selective alpha 1-adrenergic inhibitor (prazosin, 1.0 to 2.0 mg/day in divided doses) was administered as a single antihypertensive agent to 10 (four men and six women, aged 52 to 76 years) hypertensive patients (systolic blood pressure [SBP] greater than or equal to 150 mm Hg or diastolic blood pressure [DBP] greater than or equal to 90 mm Hg) with non-insulin-dependent diabetes mellitus (NIDDM) for up to 20 weeks. Blood pressure, glucose tolerance and immunoreactive insulin (IRI) response to 75 gm oral glucose load, hemoglobin A1 (Hb A1), serum lipid profile, and serum apolipoprotein were examined before and after treatment. SBP and DBP were significantly reduced at 20 weeks after treatment with the selective alpha 1-adrenergic inhibitor (SBP 167 +/- 6 mm Hg versus 152 +/- 7 mm Hg; DBP 81 +/- 3 mm Hg versus 76 +/- 3 mm Hg, (p less than 0.05 and p less than 0.01, respectively). Glucose tolerance and IRI response to glucose load were not significantly changed at 4 and 12 to 20 weeks after selective alpha 1-inhibitor treatment compared with the baseline data before treatment; the level of Hb A1 was not significantly changed at 4 and 20 weeks after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1991

Specific antibodies against the stress-inducible 72-kDa protein, a member of the heat-shock protein hsp70, in healthy human subjects.

1. On Western blot analysis, serum IgG from a healthy human subject reacted with a stress-induced protein, having an apparent molecular mass of 70 kDa, from PC12 cells. 2. This serum IgG also reacted with hsp70 (70-kDa heat-shock protein) purified from the bovine brain. 3. In 5 out of 34 healthy human subjects, IgG antibodies against hsp70 were detected. 4. These antibodies were directed against the stress-inducible 72-kDa protein, but did not cross-react with the constitutive 73-kDa protein.

Adult↗
PubMed1991

Micro-observation and characterization of bonding between bone and HA-glass-titanium functionally gradient composite.

Bioactive composite implants consisting of hydroxyapatite (HA)-glass (G) ceramic layer and Ti-6AI-4V alloy, so-called HA-G-Ti functionally gradient implant, were provided for investigating the bonding behaviour of bone to the implant in vivo. The HA-G-Ti composites were implanted in femur and tibia of dog for various periods (1-12 month). Microstructural appearance of the interface between bone and the HA-G coating layer as well as the transverse sections of the HA-G coating layer and further apposition of bone to the implant have been studied in detail with SEM. The ingress of collagen fibres into the HA-G coating layer and the deposit of apatite on the collagen fibres and HA crystal grains being containing within the HA-G coating layer have been observed. Radiographical experiments indicate that the reparative process in the bone tissue surrounding the implants is markedly ahead even at one month after implantation. FT-IR measurement and X-ray diffraction were carried out for studying the characterization of the calcified bone matrix around the implants and the new bone proliferated along the HA-G-coated face (surface).

Animals↗
PubMed1991

Combined effects of synthetic lipid A analogs and muramyl dipeptide on antitumor activity against Meth A fibrosarcoma in mice.

Combined effects of chemically synthesized lipid A analogs, the compound A-171 (acylglucosamine-4-phosphate with (R)-3-hydroxytetradecanoyl and (R)-3-hydroxytetradecanoyloxy]tetradecanoyl group at the C-2 and C-3 positions), or the compound A-172 (with (R)-3-hydroxytetradecanoyloxy]tetradecanoyl and (R)-3-tetradecanoyloxytetradecanoyl group at the C-2 and C-3 positions), and muramyl dipeptide (MDP) on antitumor activity against Meth A fibrosarcoma, were examined. Meth A fibrosarcoma cells (5 X 10(5)) were inoculated intradermally into BALB/c mice on day 0, compound A-172 and/or MDP were administered intravenously (i.v.) on day 7. Although the antitumor activity by single i.v. injection of A-172 (50 micrograms/mouse) with MDP (10 micrograms) was weaker than that of 50 micrograms of synthetic lipid A analogs (506), or 10 micrograms of bacterial lipopolysaccharide (LPS) with MDP, A-172 alone and with MDP exhibited tumor inhibition rates of 49.0 and 70.6%, respectively. When A-171 (50 micrograms) with MDP (10 micrograms) was administered i.v. twice (days 7 and 10) into mice inoculated Meth A fibrosarcoma, two of five mice caused complete tumor regression. Furthermore, L929 cell lysis by the combination of A-171, A-172 with MDP was higher than that by the analogs or MDP alone, suggesting that the lipid A analogs of monosaccharide type as well as LPS are able to enhance the production of tumor necrosis factor in the presence of MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

Hydrophobic core of molten-globule state of bovine carbonic anhydrase B.

The interaction which stabilizes the intermediate state of the protein folding and/or unfolding is important for understanding the structure formation mechanism of proteins. The partitioning of a hydrophobic fluorescence probe, pyrene, into the core of a 'molten globule' structure of bovine carbonic anhydrase B was measured, revealing a partition coefficient of about 10(4). The result leads to the conclusion that the compact structure of the molten-globule state is formed by the hydrophobic interaction, as detergent micelles are formed by the same interaction.

Animals↗
PubMed1991

Membrane conductance of an electroporated cell analyzed by submicrosecond imaging of transmembrane potential.

Transmembrane potential was induced in a sea urchin egg by applying a microsecond electric pulse across the cell. The potential was imaged at a submicrosecond time resolution by staining the cell membrane with the voltage-sensitive fluorescent dye RH292. Under moderate electric fields, the spatial distribution of the induced potential as well as its time dependence were in accord with the theoretical prediction in which the cell membrane was regarded as an insulator. At higher field intensities, however, the potential apparently did not fully develop and tended to saturate above a certain level. The saturation is ascribed to the introduction of a large electrical conductance, in the form of aqueous openings, in the membrane by the action of the induced potential (electroporation). Comparison of the experimental and theoretical potential profiles indicates that the two regions of the membrane that opposed the electrodes acquired a high membrane conductance of the order of 1 S/cm2 within 2 microseconds from the onset of the external field. The conductance was similar in the two regions, although permeability in the two regions of the membrane long after the pulse treatment appeared quite different.

Animals↗
PubMed1991

Immunohistochemical study on the developing optic nerves in human embryos and fetuses.

For the purpose of investigating the time of development and myelination of the optic nerve, we applied immunohistochemical stains to the optic nerves of 26 human embryos and fetuses aged 6-39 weeks. The minimum diameter of the optic nerve's cross section increased with the development of embryos; 0.15 mm at the 9th week, 0.4 mm at the 11th week, 1.5 mm at the 24th week, and 2.1 mm at the 32nd week. With regard to myelin basic protein (MBP), the localization could not be observed at 28 gestational weeks. The MBP was proved to be positive in oligodendrocytes of the optic nerve at the age of the 32nd gestational week. The localization of glial fibrillary acidic protein (GFAP) was proved partially in astrocytes around the optic nerve in the case of 24 gestational weeks. The remarkable localization of GFAP-positive astrocytes inside the nerve fibers was proved at the 27th gestational week. The histological appearance of GFAP-positive cells advanced to that of MBP-positive ones after 8 weeks interval. The degree of MBP staining was less marked than that of GFAP in examined fetal cases. These results suggest that astrocytes and oligodendrocytes correlate to the developmental growth and myelination of the optic nerves during the fetal development.

Embryonic and Fetal Development↗
PubMed1991

Dual-view microscopy with a single camera: real-time imaging of molecular orientations and calcium.

A new microscope technique, termed "W" (double view video) microscopy, enables simultaneous observation of two different images of an object through a single video camera or by eye. The image pair may, for example, be transmission and fluorescence, fluorescence at different wavelengths, or mutually perpendicular components of polarized fluorescence. Any video microscope can be converted into a dual imager by simple insertion of a small optical device. The continuous appearance of the dual image assures the best time resolution in existing and future video microscopes. As an application, orientations of actin protomers in individual, moving actin filaments have been imaged at the video rate. Asymmetric calcium influxes into a cell exposed to an intense electric pulse have also been visualized.

Actin Cytoskeleton↗
PubMed1991

Pathophysiological role of augmented atrial natriuretic polypeptide gene expression in DOCA-salt hypertension. Effects of atrial natriuretic polypeptide monoclonal antibody.

To elucidate the pathophysiological significance of endogenous atrial natriuretic polypeptide (ANP) in hypertension, we investigated the biosynthesis and secretion of ANP in deoxycorticosterone acetate (DOCA)-salt hypertensive rats and also examined the effect of passive immunization with monoclonal antibody raised against alpha-rat ANP on the development of hypertension in DOCA-salt rats. The plasma ANP level in DOCA-salt rats was significantly elevated in comparison to control rats. While the atrial ANP concentration in DOCA-salt rats was not significantly altered, the atrial level of ANPmRNA in DOCA-salt rats was two-fold higher than that in control rats. These results suggest the augmented biosynthesis of ANP in the atrium and the oversecretion of ANP from the heart in DOCA-salt rats. The levels of ANP and ANPmRNA in the ventricle of DOCA-salt rats exhibited significant increases, compared with those in control rats, suggesting the induction of ANP gene expression in the ventricle of DOCA-salt hypertensive rats under pre/after overload. Weekly intravenous administrations of monoclonal antibody with high affinity for alpha-rat ANP significantly augmented the rise in blood pressure of DOCA-salt rats. These results support the hypothesis that the augmented secretion of ANP is one of the defensive mechanisms to counteract high arterial pressure in this model of hypertension.

Animals↗
PubMed1991

Altered noradrenergic projection to hypothalamus via baroreflex in spontaneously hypertensive rats.

To determine whether noradrenergic projections to the posterior hypothalamus via baroreflex are altered in the hypertensive state, the extracellular norepinephrine (NE) content of the posterior hypothalamus was measured in both spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) after sinoaortic denervation (SAD) or sham operation. In WKY, blood pressure (BP) and extracellular NE content 24 h after SAD were significantly higher than those of sham-operated rats. Contrarily, SAD did not increase both BP and NE in the posterior hypothalamus of SHR. These results suggest that the noradrenergic pathway via the baroreflex is impaired in SHR. This mechanism may play an important role in the development and maintenance of hypertension in SHR.

Adrenergic Fibers↗
PubMed1991

Presence of carcinogenic heterocyclic amines in urine of healthy volunteers eating normal diet, but not of inpatients receiving parenteral alimentation.

For estimation of human exposures to carcinogenic heterocyclic amines, the amounts of four compounds, 3-amino-1, 4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), in human urine were measured. Twenty-four hour urine specimens were collected from ten healthy volunteers eating normal diet (five males and five females) and three inpatients (two males and a female) receiving parenteral alimentation, and the levels of the four heterocyclic amines were measured by HPLC after partial purification by treatment with blue cotton and ion exchange column chromatography. Trp-P-1, Trp-P-2, PhIP and MeIQx were detected in the 24 h urine samples of all healthy volunteers at levels of 0.04-1.43 ng, 0.03-0.68 ng, 0.12-1.97 ng and 11-47 ng respectively. As 1.8-4.9% of an oral dose of MeIQx is reported to be excreted unchanged in the urine, the daily exposure of humans to MeIQx was estimated to be 0.2-2.6 micrograms/person. The four heterocyclic amines were not detected in the urine of parenterally fed inpatients. These results indicate that humans are continually exposed to carcinogenic heterocyclic amines in food, and these compounds may not be formed endogenously.

Adolescent↗
PubMed1991

Early and delayed I-123 IMP SPECT in epileptic patients with partial seizures and normal CT.

Forty-six epileptic patients with partial seizures and normal CT underwent 48 examinations of early and delayed SPECT using I-123 IMP in the interictal phase. One of them underwent a follow-up SPECT in a more stable state compared to the first SPECT. Another patient, with informed consent, underwent a follow-up SPECT in combination with pharmacologic activation with bemegride. Early SPECT was performed 30 minutes after an IMP injection and delayed SPECT 4 to 4 1/2 hours later. Temporal changes in uptake pattern were visually classified into six types and compared with known patterns of SPECT uptake in relation to ischemic, hyperemic, and other changes. These were also correlated with the amount of epileptic activity seen on the EEG.

Adolescent↗
PubMed1991

Concentrations of endothelin-1 in human amniotic fluid at various stages of pregnancy.

To examine the possible role of endothelin in the initiation of parturition, endothelin-1-like immunoreactivity (ET-1-LI) in the amniotic fluid (AF) was determined by a sensitive radioimmunoassay (RIA) system. The concentrations of ET-1-LI in AF were 24.7 +/- 6.1 pg/ml (mean +/- SD, n = 6) at the second trimester and were significantly increased to 40.4 +/- 15.1 pg/ml (n = 6) at term. These ET-1-LI concentrations are about three- to fourfold higher than those observed in the maternal plasma. The gel permeation chromatography (GPC) profile of ET-1-LI extracted from second-trimester AF indicated that the ET-1-LI consisted of only one component of 6kET, the molecular weight of which was 6,000, larger than big ET-1. In contrast, ET-1-LI in the AF at term consisted of two components, ET-1 and 6kET. These findings suggest that the level of biologically active ET-1 in the AF increases markedly from second trimester toward term. A significant amount of ET-1-LI was also detected in the supernatant of amnion cell culture. The level of ET-1-LI in the culture medium after 12 h of incubation was almost comparable with that in AF at term. Thus, it is suggested that amnion tissue may be the major source of ET-1-LI in the AF. Together with the fact that ET-1 increases cytoplasmic calcium ion in the target cell, the results of present study raise the possibility that endothelin plays an important role in the initiation of parturition by triggering the production of prostaglandins in fetal membranes.

Amniotic Fluid↗