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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 523 records · Page 29Linked to original sources
PubMed1996

Pigmentation abnormalities in systemic scleroderma examined by using a colorimeter (Choromo Meter CR-200).

Cutaneous colors of the dorsum of the hands (A), the distal forearms (B; 5 cm from the wrists), the proximal forearm (C; proximal 1/3 from the elbow) and sternal skin region (D) in patients with systemic scleroderma (73 cases; M:F = 16:57) systemic lupus erythematosus (SLE) or dermatomyositis (27 cases; M:F = 7:20) and healthy controls (HC) (36 cases; M:F = 8:28) was characterized by a XYZ colorimetric system (CIE, 1931) using a colorimeter (Choromo Meter CR-200, Minolta Camera Co. Ltd., Osaka). The index Y, which means color value shows a lower value in male HC and in patients with systemic scleroderma, especially in the more severe type with hyperpigmentation (score 5-6; the system proposed by Ishikawa) than that of female HC. The values of indices x and y, which relate to reddish (erythema with hyperpigmentation) and greenish color (pale), respectively, were higher in the exposed portion of the severe type of systemic scleroderma with hyperpigmentation, especially male and older patients, and in unexposed portions of the female group without hyperpigmentation. Histopathologically, there was prominent pigmentation in the upper dermis of the forearm in the severe type of systemic scleroderma, so that melanin quantity may be closely related to the decrease in index Y. There was no statistical significance in the value of indices Y, x and y between HC, SLE and dermatomyositis. This method may contribute not only to diagnosis of systemic scleroderma and differentiation from other collagen diseases, but also studies of clinical follow-up and effects of medication.

Adult↗
PubMed1996

Circadian variations of plasma levels of blood coagulation/fibrinolysis molecular markers in progressive systemic sclerosis (PSS).

We measured plasma levels of the blood coagulation/fibrinolysis molecular markers, thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA), alpha 2-plasmin inhibitor plasmin complex (PIC), beta-thromboglobulin (beta-TG), platelet factor 4 (PF4), at 6:00, 12:00, 18:00 and 24:00 in 10 female patients with progressive systemic sclerosis (PSS) (severe and mild sclerosis groups, each n = 5), 3 cases of dermatomyositis (DM) (M:F = 2:1) and 5 female healthy controls (HC). Corticosteroid (predonisolon; 20-25 mg/day) was administered orally in six patients with PSS and dermatomyositis longer than one month. Plasma levels of TAT increased more than 3 ng/ml in 8 out of 10 cases (80%) of PSS, while the levels increased in only 2 of 8 cases (25%) of the non-PSS groups (DM and HC). The severe sclerosis group of PSS showed a peak at 6:00 in the circadian variations of plasma levels of TAT and FPA, while the mild sclerosis group of PSS showed a peak at 12:00 or 24:00, and both DM and HC at 24:00. However, there was no significant peak in circadian variations of the plasma levels of PIC in the severe sclerosis group of PSS, although there was a peak at 24:00 in other diseases. The synchronized peaks of TAT and PIC were seen in 4 of 8 cases (50%) of the non-PSS group. On the other hand, this synchronization was only detected in 1 of 10 cases (10%) of PSS. The plasma levels of beta-TG and PF4 increased in 8 of 10 cases (80%) of PSS, but these levels did not increase in 8 non-PSS cases. Circadian variation of plasma levels of beta-TG showed a peak at 6:00 in the severe sclerosis group of PSS, while the mild sclerosis group of PSS, DM and HC revealed peaks at different times of 18:00, 24:00 and 12:00, respectively. Additionally, the plasma levels of beta-TG increased more than those of PF4 in the treated group with corticosteroid, although both beta-TG and PF4 revealed a statistically significant correlation in the non-treated group. These results may suggest abnormalities of not only platelet activity, but also of blood coagulation/fibrinolysis system in both severe and mild sclerosis groups of PSS.

Adult↗
PubMed1996

Positron-labeled antioxidant 6-deoxy-6-[18F]fluoro-L-ascorbic acid: increased uptake in transient global ischemic rat brain.

The in vivo uptake and distribution of 6-deoxy-6-[18F]fluoro-L-ascorbic acid (18F-DFA) were investigated in rat brains following postischemic reperfusion. Global cerebral ischemia was induced in male Wistar rats for 20 min by occlusion of four major arteries. Two time points were chosen for 18F-DFA injection to rats subjected to cerebral ischemia, at the start of recirculation and 5 days following recirculation. The rats were then killed at 2 h after tail-vein administration of 18F-DFA and tissue radioactivity concentration was determined. Increased uptake of radioactivity in particular brain regions, including the cerebral cortex, hypothalamus, and amygdala following injection of 18F-DFA, compared to the sham-operated control, was observed 5 days after reperfusion. Similar results were also obtained in in vitro experiments using brain slices. Abnormal in vivo accumulation of 45Ca, a marker of regional postischemic injury, was observed in these brain regions in tissue dissection experiments. Furthermore, metabolite analysis of nonradioactive DFA using 19F-NMR showed that DFA remained intact in the postischemic reperfusion brain. The present results indicate that 18F-DFA increasingly accumulates in damaged regions of postischemic reperfusion brain.

Animals↗
PubMed1996

Hyperattenuating rim on noncontrast CT of the liver: probable peritumoral sparing of fatty infiltration.

CT scans showing a hyperattenuating rim within the liver were retrospectively evaluated in 10 patients to clarify the character, aetiology and clinical significance. All patients had hepatic tumours (7 cavernous haemangiomas in 6 patients, 3 metastatic tumours and 1 hepatocellular carcinoma) as well as fatty infiltration of the liver. Typical features of the hyperattenuating rim on noncontrast CT of the liver included (1) attenuation similar to that of the spleen, (2) a circular or semicircular shape, (3) a width of a few millimeters, (4) peritumoral localization and (5) loss of visualization with contrast enhancement. No such rims were noted around hepatic tumours unassociated with fatty infiltration. Peritumoral sparing of fatty infiltration was inferred. A hyperattenuating rim on noncontrast liver CT, although rare, suggests the presence of a hepatic tumour in fatty liver.

Adult↗
PubMed1996

Calcium spirulan, an inhibitor of enveloped virus replication, from a blue-green alga Spirulina platensis.

Bioactivity-directed fractionation of a hot H2O extract from a blue-green alga Spirulina platensis led to the isolation of a novel sulfated polysaccharide named calcium spirulan (Ca-SP) as an antiviral principle. This polysaccharide was composed of rhamnose, ribose, mannose, fructose, galactose, xylose, glucose, glucuronic acid, galacturonic acid, sulfate, and calcium. Ca-SP was found to inhibit the replication of several enveloped viruses, including Herpes simplex virus type 1, human cytomegalovirus, measles virus, mumps virus, influenza A virus, and HIV-1. It was revealed that Ca-SP selectively inhibited the penetration of virus into host cells. Retention of molecular conformation by chelation of calcium ion with sulfate groups was suggested to be indispensable to its antiviral effect.

Antiviral Agents↗
PubMed1996

Differential expression of Fc receptors for IgG by monocytes and granulocytes from neonates and adults.

The immature neonatal immune system is thought to result in increased risk of infection. Receptors for the Fc moiety of IgG (Fc gamma R) are important in antibody-mediated clearance of microbes by granulocytes and monocytes/macrophages. As an approach to understanding their role in neonatal life, we have compared the constitutive expression of the three Fc receptors--Fc gamma RI (CD64), Fc gamma RII (CD32) and Fc gamma RIII (CD16)--by neonatal and adult blood monocytes and granulocytes using quantitative immunofluorescence by flow cytometry. Our results confirm that there is a small subpopulation of Fc gamma RIII-positive monocytes in adult blood, and furthermore show that this is absent or at a low percentage in cord blood samples. However, the main population of cord blood monocytes expresses low, but significantly higher levels of Fc gamma RIII than adult monocytes. No differences were seen in the quantitative expression of Fc gamma RI and Fc gamma RII. Neonatal granulocytes expressed significantly higher levels of both Fc gamma RI and Fc gamma RII but significantly lower levels of Fc gamma RIII. The data are discussed in terms of the possible role of cytokines and susceptibility to infection.

Adult↗
PubMed1996

Inhibition of hereditary hepatitis and liver tumor development in Long-Evans cinnamon rats by the copper-chelating agent trientine dihydrochloride.

Trientine dihydrochloride (trientine) is an alternative medicinal copper chelating agent for patients with Wilson's disease of penicillamine intolerance. We examined the effects of trientine on the spontaneous development of hepatitis and hepatic tumors, by its short-term and long-term administration to Long-Evans cinnamon (LEC) rats with an accumulation of copper in the liver, as animal models of Wilson's disease. Male rats were given trientine in their drinking water at 1500 ppm for 18 weeks, from 6 weeks to 24 weeks of age in short-term experiment, and 1500 ppm for 27 weeks then 750 ppm for 52 weeks, from 8 to 87 weeks of age in the long-term experiment. Development of hepatitis was observed in the control LEC rats at 18 weeks of age. They had high levels of plasma transaminases (glutamic oxaloacetic transaminase [GOT], glutamic pyruvic transaminase [GPT]), and on pathological examination, hepatocyte destruction was observed. Histological findings revealed that short-term administration of trientine inhibited the development of hepatitis remarkably. The plasma GOT and GPT levels of treated animals were only slightly higher than those of normal LEA (Long-Evans with agouti coat color) rats, a sibling line of LEC rats. Copper levels in the liver were decreased by a maximum of 50 percent. In the long-term administration of trientine, the incidence of hepatic cell carcinoma (HCC) in the treated rats was 67 percent that of the untreated LEC rats, and the number of HCCs per rat in the treated group was 0.7 +/- 0.5, being significantly lower as compared with 4.7 +/- 3.5 in the untreated rats. Additionally, the development of cholangiofibrosis in LEC rats was completely prevented by long-term administration of the agent. The copper level in the liver of treated rats was reduced by 33 percent at 87 weeks of age. Development of HCC in LEC rats might be partly, but not totally, because of copper accumulation. No effects on the levels of copper, iron, or zinc in the liver of LEA rats was detected, and no adverse effects were detected in either LEC or LEA rats after both short- and long-term administration of trientine in drinking water.

Alanine Transaminase↗
PubMed1996

Rate constant of gadolinium (Gd)-DTPA transfer into chronic subdural hematomas.

Gadolinium (Gd) DTPA concentrations in subdural fluid and arterial blood were measured following intravenous Gd-DTPA injection by ion coupled plasma emission spectrometry in 31 chronic subdural hematomas and 12 with subdural effusions. Dynamic biological modeling analysis was used to calculate the unidirectional transfer rate constant (K) for Gd-DTPA influx into the subdural fluid. The Gd concentrations in subdural hematomas and subdural effusions were 36.3 +/- 3.7 nmol ml(-1) and 80.0 +/- 14.0 nmol ml(-1), respectively. The transfer rate constants (K) for subdural hematomas and subdural effusions were 12.4 +/- 1.5 (x10(-4)) min(-1) and 19.7 +/- 2.2(x10(-4)) min(-1), respectively. The Gd concentration and transfer rate constant for subdural effusions were significantly (p<0.05) higher than for subdural hematoma. The Gd transfer rate constant was significantly correlated with the interval from head injury to operation. The present study shows that the immature outer membrane has a high transfer rate constant, allowing extravasation of plasma components into the subdural space and increasing the volume of the subdural effusion; the rate constant decreases with aging of the subdural hematoma.

Adolescent↗
PubMed1996

An aminopeptidase inhibitor, bestatin, enhances progesterone and oestradiol secretion by porcine granulosa cells stimulated with follicle stimulating hormone in vitro.

We examined the presence of cell surface aminopeptidase on cultured porcine granulosa cells by employing the aminopeptidase assay using alanine-p-nitroanilide and histochemical staining using L-leucyl-beta-naphthylamide. Porcine granulosa cells obtained from follicles 4-5 mm in diameter were cultured for 7 days. The aminopeptidase assay showed that the porcine granulosa cell culture had aminopeptidase activity and that this activity was inhibited in a dose-dependent manner by bestatin which binds to cell surfaces and inhibits cell surface aminopeptidases. Histochemical staining also indicated that cultured granulosa cells had aminopeptidase activity. Porcine granulosa cells were cultured in the presence or absence of porcine follicle stimulating hormone (FSH, 3.125 nmol/l) and/or bestatin (0.4, 4.0 and 40.0 micrograms/ml) for 7 days, and the production of progesterone and oestradiol was measured. In the presence of porcine FSH, the production of progesterone and oestradiol by granulosa cells was increased significantly by approximately 5- and 2-fold respectively. These increases were enhanced further by bestatin (40.0 micrograms/ml). In the absence of porcine FSH, progesterone production was enhanced by bestatin (40.0 micrograms/ml), whereas no significant effect of bestatin on oestradiol secretion was observed. These findings indicate that the inhibition of membrane-bound aminopeptidase(s) on the cell surfaces affects the steroidogenesis of granulosa cells, and that these aminopeptidase(s) are important regulators of granulosa cell differentiation.

Aminopeptidases↗
PubMed1996

Blood pressure variability at annual periodic health examination for employees and cardiovascular risk factors.

The employees with hypertension at the annual periodic health examination (HE) for employees in Japan usually receive a re-examination of blood pressure (BP) on another day and are often found to be normotensive. In this study, we analyzed data from the HE at the workplace to determine whether or not such employees should receive medical care. Two groups of subjects were selected. One group (group 1) was composed of 50 subjects with normotension at the HE (controls). Another group (group 2) was composed of 33 subjects with hypertension at the annual HE but with normotension in re-examinations. Cardiovascular risk factors were significantly higher in group 2 than in group 1: mean values of the body mass index (group 1, 22 +/- 2.7 vs. group 2, 24.3 +/- 3.1 kg/m2, p < 0.01), total cholesterol (group 1, 197 +/- 36 vs. group 2, 222 +/- 42 mg/dl, p < 0.01), and low density lipoprotein (group 1, 118 +/ 32 vs. group 2, 137 +/- 38 mg/dl, p < 0.05). The proportion of the employees with high-normal BP in group 2 (42.5%) was significantly higher than that in group 1 (28.0%) (p < 0.01). These indicate that the employees with hypertension at the annual HE but with normotension in the re-examination require further medical attention and should receive medical supervision. The occupational physician should supervise these employees.

Adult↗
PubMed1996

An aminopeptidase inhibitor, bestatin, enhances gonadotrophin-stimulated ovulation in mice.

The role of aminopeptidases in follicular growth and/or ovulation in vivo was examined. We injected an inhibitor of cell-surface aminopeptidases, bestatin (4 mg/ml, 100 microliters), i.p. four times during 2 days into 20 day old female ICR mice, in which follicular growth and ovulation were stimulated by pregnant mare's serum gonadotrophin (PMSG, 5 IU) and human chorionic gonadotrophin (HCG, 5 IU). The number of ovulated oocytes was estimated by counting the number of oocytes in the oviduct 19 h after HCG injection. The mean +/- SD number of ovulated oocytes in bestatin-treated mice was significantly higher than that in control mice [47.00 +/- 18.13 (n = 26) versus 35.90 +/- 10.14 (n = 28), P < 0.01]. To confirm the direct effect of bestatin on the ovary, bestatin (2 mg/ml, 3 microliters) or its stereoisomer (2 mg/ml, 3 microliters) with very weak inhibitory activity was unilaterally injected into the ovarian bursa 24 h before the administration of PMSG. As a control, buffer (3 microliters) was injected into the contralateral bursa. In some experiments, bestatin (2 mg/ml, 3 microliters) was injected just before HCG administration. The administration of bestatin via the ovarian bursa prior to PMSG administration significantly increased the number of ovulated oocytes per oviduct from the treated compared with the contralateral ovary [23.70 +/- 9.61 versus 17.10 +/- 5.83 (n = 25), P < 0.01], whereas its stereoisomer elicited no significant effects. The administration of bestatin just before HCG administration also had no effect. These findings indicate that membrane-bound peptidase(s) present on murine ovarian cells is an important regulating factor(s) of follicular growth and/or ovulation.

Aminopeptidases↗
PubMed1996

A differentiation antigen of human large luteal cells in corpora lutea of the menstrual cycle and early pregnancy.

To investigate the mechanism(s) of luteal cell differentiation, we raised a monoclonal antibody, HCL-1, against human large luteal cells. The antigen was undetectable in growing and preovulatory follicles by immunohistochemistry. The antigen was initially detected on centrally located luteinizing granulosa cells during CL formation. During the midluteal phase, the antigen was expressed at high levels on large luteal cells. Large luteal cells in the CL during late luteal phase and early pregnancy also expressed high levels of HCL-1 antigen, whereas small luteal cells at any stage of the CL did not. Granulosa cells in some atretic follicles weakly expressed HCL-1 antigen. Immunofluorescence staining of enzymatically dispersed luteal cells from human mature CL revealed that HCL-1 antigen was present on the cell surface of large luteal cells. Human granulosa cells isolated from patients who had undergone in vitro fertilization treatment were cultured for 7 days. Indirect immunofluorescence detected HCL-1 antigen on only a few granulosa cells after culture for 1 day and on almost all granulosa cells after culture for 7 days. Flow cytometry of 7-day-cultured cells showed that the percentages of positivity for HCL-1 antigen as well as the mean fluorescence intensities of granulosa cells cultured with hCG (1 IU/ml) were significantly lower than those of the controls (without treatment) (44.3 +/- 3.2% vs. 62.9 +/- 4.0%. p < 0.01; 60.9 +/- 6.7 vs. 82.1 +/- 7.6, p < 0.05). By contrast, the mean fluorescence intensities of cells cultured with interleukin- 1 alpha (10 ng/ml, 105 +/- 6.3, p < 0.05) and tumor necrosis factor alpha (10 ng/ml, 112 +/- 11.2, p < 0.05) were significantly higher than those of controls. These findings showed that the cell surface antigen detected on human large luteal cells by HCL-1 was differentiation-related, and that large luteal cells in the CL of pregnancy are derived from granulosa cells via large luteal cells in the CL of the menstrual cycle.

Adult↗
PubMed1996

Epidemiological analysis of prognosis of 496 Japanese patients with progressive systemic sclerosis (SSc). Scleroderma Research Committee Japan.

For the first time, we performed an epidemiological study of SSc in Japan to study the factors influencing prognosis, survival rate and cause of death of Japanese SSc patients and to compare our data with those from foreign countries. Prognosis of 496 Japanese patients with progressive systemic sclerosis (SSc) was analyzed based on clinical data described in case cards provided by the members of the Scleroderma Research Committee of the Japanese Ministry of Health and Welfare. The essential observation period was from 5 to 20 years, at ending in 1994. Ninety patients died (males 11, females 79). The age of onset of the deceased patients was significantly higher than that of surviving patients (deceased, 45.6 yrs, surviving 41.3 yrs). Statistically significant factors for a poor prognosis were as follows: Barnett type III > type II > type I, positive for anti-Scl-70 antibody, negative for anti-centromere antibody. The survival rate at 5 years after the onset of the disease was 0.937, followed by 0.82 at 10 years, 0.567 at 20 years and 0.40 at 30 years after the onset. Sex was not a predictor for prognosis, although male patients died at an earlier stage of the disease. The most common causes of death were heart failure, pulmonary insufficiency, lung fibrosis, and renal failure. Twenty-four patients had cancer of which 13 were lung cancers. The current status of the survival rate and prognostic factors of 496 Japanese SSc patients is summarized. In future, more well-controlled studies using the same criteria should be performed for the better understanding and management of SSc.

Adult↗
PubMed1996

Analysis of the phospholipase C gene of Clostridium perfringens KZ1340 isolated from Antarctic soil.

Clostridium perfringens KZ1340 isolated from Antarctic soil was first classified as Clostridium plagarum and later as a lecithinase-negative variant of C. perfringens. Although the strain produced no detectable lecithinase (phospholipase C, PLC) activity in the culture supernatant, it was shown by Southern blot hybridization to possess a PLC-encoding gene (plc). To determine the cause of the PLC deficiency, we cloned and sequenced the plc gene from KZ1340. The deduced amino acid sequence consists of 398 amino acid residues, coinciding with those of the plc genes previously determined. Tyrosine was substituted for histidine at amino acid position 148, which is thought to bind a zinc ion essential for PLC activity. Northern blot analysis revealed that KZ1340 expressed the plc gene at an extremely low level. Furthermore, the plc gene cloned from C. perfringens strain 13 into a plasmid was expressed weakly in KZ1340, compared to that in strain 13. This indicates that the former strain represses plc gene expression in trans. When a phylogenetic tree of plc genes was constructed, the KZ1340 plc gene formed a monophyletic branch along with those of various other C. perfringens strains, supporting the classification of the strain as a variant of C. perfringens.

Amino Acid Sequence↗
PubMed1996

Suppressing effects of 6-(2,5-dichlorophenyl)-2,4-diamino-1,3,5-triazine and related synthetic compounds on azoxymethane-induced aberrant crypt foci in rat colon.

The modifying effects of dietary administration of 6-(2,5-dichlorophenyl)-2,4-diamino-1,3,5-triazine and 5 related compounds on the occurrence of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body weight) once a week for 3 weeks to induce ACF. They also received the diet containing 200 ppm test compound for 5 weeks, starting one week before the first dosing of AOM. At the termination of experiment, all of the compounds had caused a significant reduction in ACF frequency, which might be associated with suppression of the expression of proliferation biomarkers. The apoptotic index in the colonic mucosal epithelium of rats killed at 6 h after the first AOM exposure revealed no blocking activity of the compounds.

Animals↗
PubMed1996

Detection of scleroderma with capillaroscopic abnormalities of nailfolds.

BACKGROUND: Systemic scleroderma is a problem in Gifu Prefecture, Japan. METHODS: Three hundred and thirty-two men and 731 women over 30 years of age, who attended the residents' health examination in K town of Gifu Prefecture (population 4835 persons over 30 years of age) had a dermatologic examination. Antinuclear antibody was determined in 85 persons (14 men, 71 women; age 30 to 72 years) who had Raynaud's phenomenon or various clinical features related to systemic scleroderma. Of these 85 persons, 19 agreed to a capillaroscopic examination and of these, 16 showed some capillaroscopic abnormalities. Biopsy specimens of three women among these 16 individuals with capillaroscopic abnormalities were examined also histopathologically. RESULTS: All samples taken from the forearm skins showed thick and packed bundles of collagen with hyalinization and thickened small blood vessels in the dermis, similar to histopathologic features of systemic scleroderma, although all these women had only a sausage-like swelling of the fingers and a shortened frenulum of the tongue. These results suggest that the prevalence of systemic scleroderma can be estimated to affect more than 0.38% of the population in this town. CONCLUSIONS: Manual skills and vibration exposure may be associated with systemic scleroderma.

Adult↗
PubMed1996

In vitro evaluation of linear motor-driven total artificial heart.

This paper deals with the in vitro evaluation of a newly developed linear motor-driven total artificial heart (linear TAH). The linear TAHs have been developed and evaluated in mock testing and acute animal experiments. The new linear TAH was made based on experience with acute animal experiments. The maximum static thrust of the new linear pulse motor is 146 N with exciting current of 1.69 A. The weight and the volume of this linear TAH are 1.9 kg and 560 ml, respectively. The linear TAH has a kinetic thrust of 85 to 43 N and provides the maximum flow rate of 6.8 L/min in mock circulatory testing.

Animals↗