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Biomedical subjects

M Shimizu

Publications and source records attributed to M Shimizu.

At least 865 records · Page 48Linked to original sources
PubMed1993

Colloid liver SPECT of hepatic alveolar echinococcosis.

Seventy-one-year-old man had a liver mass. He lived in Hokkaido, where there is an epidemic of hydatic disease. Abdominal US image showed an echogenic mass. CT revealed a low density mass with an unclear margin. A 99mTc-Sulfur colloid liver SPECT study was performed to detect the liver mass. The SPECT scan was done after intravenous administration of 5 mCi of 99mTc-sulfur colloid, and it revealed a lack of uptake in the liver mass. The liver SPECT findings were correlated with subsequent CT and US imaging. Echo-guided biopsy showed a PAS-positive cuticle layer of echinococcosis in the necrotic tissue. This is the first report of a case of detection of hepatic alveolar echinococcosis by means of a colloid liver SPECT imaging procedure.

Aged↗
PubMed1993

Assessment of autonomic nervous activity by heart rate spectral analysis in patients with variant angina.

The purpose of this study was to assess the role of the autonomic nervous system in the pathogenesis of coronary artery spasm in patients with variant angina. We evaluated cardiac sympathetic and parasympathetic activity from the power (logarithmic scale) of the low-frequency (approximately 0.04 to 0.12 Hz) and the high-frequency (approximately 0.22 to 0.32 Hz) spectral components of heart rate variability with Holter monitoring in seven patients with nocturnal variant angina and in 11 healthy men who served as control subjects. None of the patients had organic coronary artery stenosis as determined by angiography. Low-frequency and high-frequency logarithmic values were calculated for each 5-minute period from 30 minutes before to immediately before each angina attack. The logarithmic low-frequency value during the 5-to-0-minute period was greater than the low-frequency values during most of the other periods (p < 0.05 - p < 0.01). The logarithmic high-frequency values during the 10-to-5-minute and 5-to-0-minute periods were greater than those during the 30-to-25-minute period (p < 0.05 and p < 0.01, respectively). These data indicate that parasympathetic activity increased during the 10 minutes before attacks of nocturnal variant angina, whereas sympathetic activity with vagal modulation increased during the 5 minutes before such attacks. The same pattern of changes in heart rate variability was found in the absence of ST-segment elevation in patients and in control subjects. So this phenomenon was not just associated with coronary spasm and variant angina. It is suggested that circadian variation in disease activity is also associated with spontaneous attacks.

Adult↗
PubMed1993

Peony and its major constituent, paeoniflorin, improve radial maze performance impaired by scopolamine in rats.

A traditional Chinese medicine, Shimotsu-to has been shown to improve spatial working memory in rats. Shimotsu-to consists of four herbs, Japanese angelica root, cnidium rhizome, peony root, and rehmannia root. In the present study, the effects of aqueous extracts of each component herb on scopolamine (0.3 mg/kg)-induced spatial working memory disruption were examined using an eight-arm radical maze task in rats. Among the four component herbs, peony root extract (0.25 and 1 g dried herb/kg, PO) exhibited the most potent antagonizing effect on the scopolamine disruption of the choice accuracy. Japanese angelica root extract (1 g dried herb/kg, PO) also significantly attenuated the scopolamine disruption, whereas neither cnidium rhizome nor rehmannia root affected it. Paeoniflorin (0.01-1 mg/kg, PO), a major constituent of peony root, dose-dependently attenuated the scopolamine-induced impairment in the choice accuracy. Scopolamine (0.3 mg/kg, IP) significantly decreased the acetylcholine contents in the hippocampus, cortex, and striatum. Although paeoniflorin alone did not affect the acetylcholine contents, pretreatment with paeoniflorin significantly prevented the scopolamine-induced decrease in the acetylcholine content in the striatum, but not in the hippocampus or cortex. These data suggest that peony root mainly contributes to the cognitive enhancing effect of Shimotsu-to and that paeoniflorin may be one of the active constituents of peony root.

Acetylcholine↗
PubMed1993

Comparative studies in molecular stability of immunoglobulin G from different species.

1. Molecular stability of immunoglobulin G (IgG) from chicken and four mammalian species (cow, goat, pig and rabbit) was compared from immunochemical and biochemical view-points. 2. IgG from cow, goat and pig showed similar stability against denaturation caused by heat, acid and denaturant treatments, while rabbit IgG was shown to be more resistant to all of the treatments than other mammalian IgGs, suggesting that rabbit IgG has a highly stable molecular structure. 3. The heat- and acid-stability of chicken IgG measured by immunochemical methods were similar to those of cow, goat and pig IgG. Conformational stability of chicken IgG measured by fluorometric and enzymatic methods, however, was lower than the mammalian IgGs, suggesting that chicken IgG has a more flexible and unstable molecular structure.

Animals↗
PubMed1993

Effect of monoclonal antibody CD4 on glomerulonephritis of ddY mice, a spontaneous animal model of IgA nephropathy.

Immunopathological studies were performed to determine whether the glomerular injuries in ddY mice, a model for IgA nephropathy (Berger's disease), are influenced by treatment with a rat monoclonal antibody (mAb) to murine CD4 molecules. The ddY mice were initially treated with intravenous injections, followed by weekly intraperitoneal injections of mAb CD4. Flow cytometry analysis showed that there was a marked decrease in the number of CD4+ T cells. In immunofluorescence, the mean intensity of IgA deposits in the renal glomerular mesangial areas and capillary walls of the treated ddY mice was significantly lower than that in saline-treated control mice of comparable ages. Glomerular mesangial expansion in the treated mice was milder than that found in the saline control mice. However, no significant differences in the level of serum IgA, urinary protein, and average number of intraglomerular cells between the treated and control ddY mice were observed. Thus, it appears that although CD4+ T cells control the amount of IgA deposits in glomeruli, other factors may be involved in the evolution of IgA nephropathy in ddY mice.

Animals↗
PubMed1993

Congenital fistula with an island of vermilion-epithelium in the paramidline of the upper lip: report of a case.

An extremely rare case of a congenital fistula with an island of vermilion-epithelium in the paramidline of the upper lip in a 17-year-old male is presented. The fistula was located in the paramidline of the philtrum dimple, and mucoid secretion from the fistula was noted. The fistula's orifice opened in the center of a well-defined, slightly dimpled, round, vermilion-like epithelium just above the vermilion border. The fistulous tract terminated in a cul-de-sac and its end was located near the alveolar process. Fistulectomy was carried out via an extra-oral approach and the epithelial defect was closed using a rotation flap. Histological examination revealed that the fistula was lined by squamous epithelium with sebaceous and mucous glands, and vermilion-like area island consisted of thin keratinized stratified squamous epithelium without skin appendages, the same as the epithelium of the lip vermilion.

Adolescent↗
PubMed1993

Genistein augments cyclic adenosine 3'5'-monophosphate(cAMP) accumulation and insulin release in MIN6 cells.

Effects of genistein on insulin release were studied using MIN6 cells, a glucose-sensitive insulinoma cell line. At the non-stimulatory concentrations of glucose, genistein did not affect insulin release, however, at the stimulatory concentrations of glucose, genistein significantly increased insulin release in a dose-dependent manner up to 20 micrograms/ml. The content of cAMP in MIN6 cells was also elevated significantly by genistein and the dose-response relationship between the genistein and cAMP accumulation was consistent with the relationship between the genistein and insulin release. These effects were inhibited by calcium antagonists or by the omission of extracellular calcium. Isobutylmethylxanthine (IBMX;0.1mM) increased both cAMP accumulation and insulin release in MIN6 cells and there were no additive effects by the addition of genistein. The accumulation of cAMP might have, at least in part, resulted from phosphodiesterase inhibition by genistein. These results suggest that genistein augments glucose-induced insulin release by the contribution of cAMP accumulation and calcium modulation which depends on extracellular calcium.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Cryptic B cell determinant in a short peptide: T cells do not induce antibody response of B cells when their determinants entirely overlap each other.

A synthetic peptide fragment encompassing residues 21-40 (F21-40) of bovine beta-lactoglobulin was used as a model antigen to investigate the relationship between T and B cell determinants. The establishment of fine specificity for these determinants in F21-40 in BALB/c mice revealed that this short peptide contained two T cell determinants, Td1 (residues 21-32) and Td2 (28-40), and that Td2 entirely overlapped the dominant B cell determinant (Bd) of residues 28-40. A truncated peptide, F25-40, was capable of strongly restimulating F21-40-primed T cells in vitro, and its binding affinity to anti-F21-40 antibodies was the same as that of F21-40, indicating that F25-40 maintained the same antigenic structure as that of region 25-40 in F21-40. However, immunization with F25-40 could not elicit specific antibodies despite priming specific T cells. From these results, Bd in F25-40 can be regarded as a cryptic B cell determinant. The absence of antibody response to F25-40 was probably caused by the complete overlapping of Td2 and Bd. This overlapping may have caused the presentation of Td2 only by professional antigen-presenting cells, but never by Bd-specific B cells possessing the potential to be differentiated to antibody-producing cells by T cell help. These findings demonstrate that the co-existence of T and B cell determinants within a single molecule does not always assure specific antibody production, which depends upon the spatial relationship between these determinants.

Amino Acid Sequence↗
PubMed1993

Responders and non-responders to bifemelane hydrochloride in Alzheimer-type and multi-infarct dementia.

Although metabolically active compounds sometime attenuate cognitive deficits of dementia patients, this mechanism has not been discussed or investigated. We hypothesized that these compounds improve cognitive disorders not by directly acting on this cognitive function, but by increasing the arousal level. Based on this hypothesis, we investigated the change of arousal levels and the improvement of intellectual functions in 10 patients with Alzheimer-type dementia (ATD) and 10 patients with multi-infarct dementia (MID) before and 3 months after pharmacotherapy using bifemelane hydrochloride. For each patient, a psychological test battery was carried out and the arousal level was evaluated using the frequency of rapid eye movements in the electro-oculogram (EOG) and the frequency analysis of electroencephalogram (EEG) before and after the treatment. Evaluation of the cognitive improvement was made and eight out of the 20 patients were regarded as responders to the treatment. The frequency of small rapid eye movements (SREM) in the EOG increased significantly only in responders and the rate of change in SREM appearance in responders was significantly different from that in non-responders. This finding suggests that a part of the intellectual improvement in ATD and MID results from the increased level of arousal.

Aged↗
PubMed1993

123I-labelled BMIPP fatty acid myocardial scintigraphy in patients with hypertropic cardiomyopathy: SPECT comparison with stress 201Tl.

123I-labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) was performed in 17 patients with hypertrophic cardiomyopathy, and was compared with 201Tl exercise stress myocardial perfusion SPECT images. Fourteen patients showed asymmetrical hypertrophy, and three demonstrated apical hypertrophy. SPECT was performed 20 min and 3 h after injection of 111 MBq 123I-BMIPP at rest. Exercise stress 201Tl SPECT was performed at 10 min and 3 h after injection and was compared with BMIPP imaging. In 13 patients BMIPP accumulation in the hypertrophied area in the 20 min image was lower than that of 3 h 201Tl uptake. Interestingly, six patients demonstrated 201Tl redistribution in the region where the uncoupling of BMIPP uptake at 20 min and 201Tl accumulation at 3 h after exercise was observed. These findings suggest that impaired fatty acid metabolism or utilization in hypertrophic myocardium and ischaemia or impaired coronary flow reserve may be one of the causes of the abnormality of fatty acid accumulation.

Adult↗
PubMed1993

Regional distribution of 201Tl during one-leg exercise: comparison with leg blood flow by plethysmography.

To validate the use of 201Tl distribution as an estimate of regional blood flow in the legs, 201Tl leg uptake was compared by whole body scintigraphy and simultaneously measured leg blood flow by plethysmography during one-leg exercise in 11 male subjects. 201Tl leg uptake ratio and leg blood flow ratio were also compared to exclude the effect of cardiac output variation in each subject. There was a good correlation between 201Tl leg uptake and leg blood flow (r = 0.85, P < 0.01, y = 0.28x + 1.00). Moreover, there was a highly linear correlation between these ratios (r = 0.98, P < 0.01, y = 0.75x + 0.13), although the 201Tl leg uptake ratio somewhat underestimated the leg blood flow ratio as exercise became strenuous. It is concluded that 201Tl leg uptake reflects regional blood flow in the legs during exercise.

Aged↗
PubMed1993

Linear porokeratosis.

A case of linear porokeratosis in a 14-year-old girl was reported. The lesions started from the right forearm and extended to the right breast. Histological examinations showed cornoid lamella in the horny layer and dyskeratotic cells in the spinous layer beneath the cornoid lamella. Linear distributions of the lesions resembled the lines of Blaschko.

Adolescent↗
PubMed1993

A case of necrobiosis lipoidica treated with systemic corticosteroid.

A 43-year-old woman had asymptomatic eruptions on the anterior sides of both legs for 5 years. Biopsy specimens revealed the typical findings of necrobiosis lipoidica. An immunofluorescence study demonstrated no deposits of immunoglobulins, complement, or fibrinogen in vessel walls. Immunohistochemical staining revealed CD4 positive lymphocytes dominating in the lesion and strong expression of ICAM-1 on the endothelial cells, giant cells, lymphocytes and dermal fibroblasts in the lesion. The eruptions resolved remarkably with oral corticosteroid therapy.

Administration, Oral↗
PubMed1993

Linear lichen planus mimicking creeping eruption.

A 42-year-old woman was referred to our hospital with a linear eruption on her right flank of two months duration. Because she had eaten loach-fish a month before she noticed the eruption, a creeping eruption due to Gnathostoma spp. was initially suspected, but the histological findings of the biopsy specimens showed typical features of lichen planus. Linear lichen planus is discussed based on the cases accumulated in the literature regarding the distribution of Blaschko lines.

Adult↗
PubMed1993

Ca2+ release from inositol 1,4,5-trisphosphate-sensitive Ca2+ store by antidepressant drugs in cultured neurons of rat frontal cortex.

The ability of antidepressant drugs (ADs) to increase the concentration of intracellular Ca2+ ([Ca2+]i) was examined in primary cultured neurons from rat frontal cortices using the Ca(2+)-sensitive fluorescent indicator fura-2. Amitriptyline, imipramine, desipramine, and mianserin elicited transient increases in [Ca2+]i in a concentration-dependent manner (100 microM to 1 mM). These four AD-induced [Ca2+]i increases were not altered by the absence of external Ca2+ or by the presence of La3+ (30 microM), suggesting that these ADs provoked intracellular Ca2+ mobilization rather than Ca2+ influx. All four ADs increased inositol 1,4,5-trisphosphate (IP3) contents by 20-60% in the cultured cells. The potency of the IP3 production by these ADs closely correlated with the AD-induced [Ca2+]i responses. Pretreatment with neomycin, an inhibitor of IP3 generation, significantly inhibited amitriptyline- and imipramine-induced [Ca2+]i increases. In addition, by initially perfusing with bradykinin (10 microM) or acetylcholine (10 microM), which can stimulate the IP3 generation and mobilize the intracellular Ca2+, the amitriptyline responses were decreased by 76% and 69%, respectively. The amitriptyline-induced [Ca2+]i increases were unaffected by treatment with pertussis toxin. We conclude that high concentrations of amitriptyline and three other ADs mobilize Ca2+ from IP3-sensitive Ca2+ stores and that the responses are pertussis toxin-insensitive. However, it seems unlikely that the effects requiring high concentrations of ADs are related to the therapeutic action.

Acetylcholine↗