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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 379 records · Page 21Linked to original sources
PubMed1992

[Bronchial hyperresponsiveness to histamine induced by intravenous administration of leukotriene C4 (LTC4) and LTD4 in guinea pigs].

Leukotriene (LT) has been suggested to play an important role in the pathogenesis of bronchial asthma. In the present study, the effects of intravenous administration of LTC4 and LTD4 on bronchial smooth muscle in guinea pigs were investigated by measurement of dynamic compliance and dynamic respiratory resistance using a formula that excludes the effect of differences in airway wall thickness. With this formula, the ratio of bronchial smooth muscle constriction by histamine can be estimated as an index of bronchial hyperresponsiveness. Administration of LTC4 and LTD4 induced airway wall edema. The ratio of bronchial smooth muscle constriction by histamine was significantly enhanced by the administration of LTC4 and LTD4. Moreover, the LT antagonist ONO-1078 inhibited the effect of LTC4 and LTD4 administration. These results suggest that LTC4 and LTD4 can be important mediators affecting bronchial hyperresponsiveness.

Airway Resistance↗
PubMed1992

[A case of herpes zoster associated with multiple cranial nerve involvement].

A 74-year-old man who had suffered from right herpes zoster ophthalmicus developed ipsilateral multiple cranial nerve involvement two weeks later. He showed right visual disturbance, total ophthalmoplegia and peripheral facial palsy. Pleocytosis and increased protein were found in CSF. Titer of VZV antibody increased in serum and CSF. CT and MRI demonstrated no abnormal findings in the brain stem. Within a month, peripheral facial palsy improved. Severe extra-ophthalmoplegia began to improve after three months, and moderately recovered. After two and a half year, visual disturbance and mydriasis showed no improvement. In this case, we speculate that localized leptomeningitis caused multiple cranial nerve involvement.

Aged↗
PubMed1991

Diabetic retinopathy in non-insulin-dependent diabetes mellitus patients: the role of gliclazide.

Diabetic retinopathy is the most common cause of human blindness between the ages of 30 and 67 in the industrialized world. Retinopathy has a multifactorial etiology. Standard treatment has aimed at correcting only disturbed glucose metabolism, but this may lead only to the partial amelioration of certain hemobiologic factors. In addition to its metabolic action, gliclazide has been shown to have specific hemobiologic properties; studies with gliclazide in animals and humans have shown significant improvements of platelet abnormalities, stimulation of prostaglandin I2 synthesis, and enhancement of fibrinolytic activity. In humans, open-label studies have shown that gliclazide treatment leads to stabilization of background retinopathy in non-insulin-dependent diabetics and, more recently, these beneficial effects have been confirmed in controlled studies lasting up to 37 months in which other sulfonylureas were used. The Japanese Diabetic Retinopathy Program studied the progression of retinopathy over a 5-year period, comparing gliclazide with other sulfonylureas and with placebo. This study showed that, with equivalent metabolic control, there was a trend toward a lower rate of deterioration and a significantly lower incidence of preproliferative retinopathy in the group receiving gliclazide compared with those receiving other sulfonylureas. Overall, the specific hemobiologic actions of gliclazide appear to offset or retard the progression of diabetic retinopathy and may have the advantage of lowering the incidence of preproliferative retinopathy.

Diabetes Mellitus, Type 2↗
PubMed1991

Characterization of antibodies to advanced glycosylation end products on protein.

Antibodies directed against advanced glycosylation end products (AGEs) formed during a Maillard reaction have been generated and characterized. Since protein-bound AGEs recognized by the antibodies were labile to acid hydrolysis, the antibodies were further characterized by using the AGE-alpha-acetyl-L-lysine methyl ester (AGE-ALME) with a brown and fluorescent property as well as the AGE-proteins. The antibodies reacted with fluorescent compounds, rather than brown pigment compounds, in the AGE-ALME. The fluorescent compounds in the AGE-ALME were separated into four fluorescent compounds by reversed-phase thin layer chromatography (TLC). Of the fluorescent compounds tested, compound 3 (Rf = 0.63), as designated on a TLC plate, showed the highest affinity for the antibodies. In addition, the antibody recognition to the cross-linked oligomers with fluorescence in the AGE-protein was investigated by using bovine pancreatic ribonuclease A (RNase), which is known as a model protein for studying AGE-induced cross-linking. Fluorescence in the AGE-RNase existed in both of the oligomers and the monomer. The cross-linked oligomers exhibited higher affinity to the antibodies than did the monomer, which has a similar degree of fluorescent intensity. These results indicate that our antibodies against cross-linked protein-bound AGEs may serve as a useful tool to elucidate pathophysiological roles of advanced Maillard reaction in diabetic complications and aging processes.

Antibodies↗
PubMed1991

[Interferon-alpha and gamma product in peripheral blood of patients with thyroid diseases].

To investigate the immunological process in various thyroid disease, we measured interferon-alpha, -gamma (IFN-alpha,-gamma, natural killer (NK) activity, and lymphocyte subsets in the peripheral blood of 27 patients with Basedow's disease (BD) (M:F = 9:18), 8 with Hashimoto's thyroiditis (HT) (2:6), 5 with idiopathic hypothyroidism (1HT) (1:4), and normal controls (C). IFN-alpha, -gamma levels were measured by bioassay with Dye-uptake method, and NK activity was measured by the LDH method. The mean +/- SD levels of IFN-gamma in BD, HT, IHT, and C (N = 217) were 173.9 +/- 88.0, 288.0 +/- 134.9, 120.4 +/- 38.0 and 173.9 +/- 88.01U/ml, respectively. The IFN-gamma level was higher in HT (p less than 0.05) than in controls, and lower in BD (p less than 0.02). Moreover, this IFN-gamma level did not correspond with the titers of thyroid hormones; TSH, anti-microsome antibody, and anti-TSH-receptor antibody in peripheral blood. However, IFN-alpha levels and NK activity in the patients of every group were similar to those in controls. The ratios of lymphocyte subsets of peripheral blood were measured by cytofluorometry with monoclonal antibodies. The mean +/- SD levels of T cells in BD, HT, IHT and C were 75.9 +/- 7.0, 83.4 +/- 7.2, 85.2 +/- 5.7, 82.3 +/- 5.8%, and those of B cells were 17.5 +/- 6.1, 10.9 +/- 4.2, 8.0 +/- 5.8, 10.9 +/- 5.0%, respectively. The ratio of T cells was higher in IHT (p less than 0.05) and lower in BD (p less than 0.01) than in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Radioimmunoassay for the determination of glycated haemoglobin.

A competitive radioimmunoassay for the quantitative determination of glycated haemoglobin was developed. The antiserum, obtained by immunizing guinea pigs with reduced glycated human albumin, was capable of identifying and quantitating the glucitollysine residues of glycated Hb after reduction with sodium borohydride. To simplify the sample preparation we introduced trichloroacetic acid precipitation to remove unreacted sodium borohydride instead of using dialysis or gel filtration. Using this procedure, our radioimmunoassay became relatively simple and provided satisfactory within- and between-run (1.3-2.8% and 1.9-5.4% coefficient of variation, respectively). The radioimmunoassay method was compared to the measurement of HbAlc by high performance liquid chromatography which is the most widely used method for quantitating glycated Hb. For this purpose glycated Hb was measured in normal glucose tolerance, impaired glucose tolerance, and diabetes mellitus groups based on WHO criteria. Both assays were able to discriminate between the normal and diabetic groups. In addition, while the determination of glycated Hb by the radioimmunoassay method was able to clearly discriminate between the normal and impaired glucose tolerance groups, the determination of HbAlc by the high performance liquid chromatography method failed to discriminate between these two groups. Moreover, 15 of the 20 impaired glucose tolerance patients exceeded the upper normal range (mean normal values + 2 SD) in radioimmunoassay. But all 20 patients with impaired glucose tolerance were within the upper normal range in HbAlc values. These results demonstrate that the measurement of glycated Hb by radioimmunoassay is more sensitive than the measurement of HbAlc by high performance liquid chromatography since it can discriminate between the normal and impaired glucose tolerance groups.

Adult↗
PubMed1991

Maternal glucose loading and fetal cardiac function in humans.

Fetal cardiac function determined using M-mode echocardiography was studied subsequent to the maternal intravenous injection of 20 g of glucose. There were 11 appropriate for date infants (AFD), 7 noneventful, light for date infants (LFD) and one high risk fetus in severe toxemia of pregnancy (Case 1), at 32-40 weeks' gestation. The fetal heart rate showed no significant changes after glucose injection in each group. The left ventricular fractional shortening and cardiac output showed significant changes, whereas the right ventricular fractional shortening and cardiac output were unchanged in both AFD and LFD. In Case 1, the adverse change was noted in both left and right cardiac functions, as compared with AFD or LFD. The combined total cardiac output in AFD increased significantly at 5 min following glucose injection, whereas that in LFD did not change significantly. On the other hand, the combined total cardiac output in Case 1 decreased markedly at 5 min after glucose injection. These findings show that the glucose loading in the mother alters cardiac function in the fetus.

Echocardiography↗
PubMed1991

Preoperative diagnostic imaging of normal-sized ovary carcinoma syndrome.

We treated a patient with a massive amount of ascites, the cytology of which contained adenocarcinoma (class V). The left ovary was slightly enlarged and the preoperative diagnostic imaging (PDI) suggested the presence of a malignancy. The right ovary was of normal size and the PDI presented no evidence of malignancy. the intra- and postoperative histological diagnosis was serous cystadenocarcinoma of the right ovary and fibroma of the left ovary. Therefore, this case can be classified as one of a normal-sized ovary carcinoma syndrome. Difficulties involved in the preoperative diagnosis of this syndrome and drawbacks of PDI are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Fetal intracranial arterial hemodynamics assessed by color and pulsed Doppler ultrasound.

Fetal intracranial arterial velocimetries were serially performed on 31 pregnant women with regular menstrual cycle, at 28-40 weeks of gestation, using color and pulsed Doppler ultrasound. The change in fetal intracranial arterial hemodynamics was based on the calculation of resistance index (RI). There was no significant difference between the RI values in the anterior cerebral artery (ACA) and middle cerebral artery (MCA) from 28 weeks to term. The RI in the posterior cerebral artery (PCA) was significantly lower than that in the ACA and MCA, respectively, from 28 weeks to term (P less than 0.001). The PI values in both the ACA and MCA remained unchanged from 28 to 33 weeks, became significantly lower from 34 to 35 weeks (P less than 0.05), and the values were fairly constant thereafter. The RI seen in the PCA showed no significant change from 28 weeks to term. This color and pulsed Doppler ultrasound assessment of fetal intracranial arterial blood flow provides a useful foundation for elucidating normal intracranial hemodynamics and will aid in avoiding misinterpretations of the different intracranial arteries.

Blood Flow Velocity↗
PubMed1991

Relationship between erythrocyte sorbitol content and diabetic microangiopathy in patients with non-insulin-dependent diabetes mellitus: the study of a diet loading test.

To determine whether erythrocyte sorbitol content could become an indicator of diabetic microangiopathy, we studied the relationship between the changes in erythrocyte sorbitol content in response to diet loading and diabetic microangiopathy in patients with non-insulin-dependent diabetes mellitus. The increase of change in erythrocyte sorbitol content (delta Sor) after diet loading (420 kcal) significantly correlated with that of plasma glucose levels (delta BS). The patients with less than or equal to 40 m/s of motor or sensory nerve conduction velocity (MCV and SCV) had significantly higher delta Sor and delta Sor/delta BS values than those with greater than 40 m/s of MCV and SCV; nevertheless, there were no significant differences in delta BS between the two groups. Furthermore there was a significant negative correlation between nerve conduction velocity and delta Sor and Delta Sor/delta BS values. On the other hand, the patients with nephropathy or retinopathy showed no significant increase in delta Sor or delta Sor/delta BS compared with patients without these complications. The results demonstrated that delta Sor and delta Sor/delta BS could become indicators of the presence or severity of diabetic neuropathy. Furthermore the more significant participation of alteration in the polyol pathway in the pathogenesis of neuropathy than of the other microangiopathies was suggested.

Aged↗
PubMed1991

Escherichia coli mediated biosynthesis and in vitro anti-HIV activity of lipophilic 6-halo-2',3'-dideoxypurine nucleosides.

A series of 6-substituted 2',3'-dideoxypurine ribofuranosides (ddP) was enzymatically synthesized with live E. coli in an effort to enhance the lipophilicity of this class of anti-human immunodeficiency virus (HIV) compounds and thereby facilitate drug delivery into the central nervous system. All 6-halo-substituted ddPs were substantially more lipophilic, as defined by their octanol-water partition coefficient (P), than their nonhalogenated congeners 2',3'-dideoxyinosine (ddI) or 2',3'-dideoxyguanosine (ddG). For this class of compounds, log P's ranged from +0.5 to -1.2 in the following order: 6-iodo, 2-amino-6-iodo greater than 6-bromo, 2-amino-6-bromo greater than 6-chloro, 2-amino-6-chloro greater than 6-fluoro, 2-amino-6-fluoro much greater than ddG greater than ddI. These compounds were evaluated in vitro for ability to suppress the infectivity, replication, and cytopathic effect of HIV. 2-Amino-6-fluoro-, 2-amino-6-chloro-, and 6-fluoro-ddP exhibited a potent activity against HIV comparable to that of ddI or ddG and completely blocked the infectivity of HIV without affecting the growth of target cells. The comparative order of in vitro anti-HIV activity was 2-amino-6-fluoro, 2-amino-6-chloro, 6-fluoro greater than 2-amino-6-bromo greater than 2-amino-6-iodo, 6-chloro greater than 6-bromo greater than 6-iodo. These compounds also exhibited potent in vitro activity against HIV-2 and 3'-azido-3'-deoxythymidine-resistant HIV-1 variants. All 2-amino-6-halo-ddPs and 6-halo-ddPs were substrates for adenosine deaminase (ADA) and were converted to ddG or ddI, respectively. In the presence of the potent ADA inhibitor 2'-deoxycoformycin, 6-halo-substituted ddPs failed to exert an in vitro antiretroviral effect. These dideoxypurine nucleoside analogues represent a new class of lipophilic prodrugs of ddG and ddI that possess the potential for more effective therapy of HIV-induced neurologic disorders.

Adenosine Deaminase↗
PubMed1991

Potential anti-AIDS drugs. Lipophilic, adenosine deaminase-activated prodrugs.

Selected acid-stable (2'-fluoro-2',3'-dideoxyarabinofuranosyl)adenine nucleosides containing methyl groups and other lipophilic functions at various positions in the adenine ring were prepared and evaluated as anti-HIV agents. The N6-methyl (1f), N6-benzoyl (1g), and 6-chloro (1i) analogues had modest activity, giving 30-50% protection to ATH8 cells infected with HIV. 2-Methyl (1d), 8-methyl (1h), and 2,N6-dimethyl (1e) substitution, as well as N1-oxide (21) formation, abolished the activity of the parent compound (1a). Several of these compounds, originally designed as agents for treating HIV in the central nervous system, were further investigated as substrates for adenosine deaminase (ADA). Kinetic experiments showed that ADA catalyzed the formation of the anti-HIV active inosine compound 1b from the N6-methyl analogue 1f in a quantitative manner. The anti-HIV activity of 1f and 1i was abolished when the ADA inhibitor, 2'-deoxycoformycin, was added to the test mixture. In contrast, the activity of 1f was significantly enhanced when ADA was added to the test system. These data indicate that 1f and 1i are prodrug forms of 1b in systems containing ADA.

Adenosine Deaminase↗
PubMed1991

Extramammary Paget's disease arising in mature cystic teratoma of the ovary.

We report a case of extramammary Paget's disease in ovarian mature cystic teratoma. The patient was a 70-year-old Japanese woman who complained of lower abdominal pain. Examination showed elevation of carcinoembryonic antigen and CA 19-9. Ultrasonography and computer tomography revealed a cystic tumor of the left ovary. The gross appearance of the resected ovary was typical for mature cystic teratoma. Microscopic observation revealed a lesion of Paget's disease within the squamous epithelium. The tumor cells had intracytoplasmic mucin and positive immunoreactivity for carcinoembryonic antigen, epithelial membrane antigen, and cytokeratin; but they were negative for S-100 protein and vimentin. On multiple and serial sections, underlying adenocarcinomas were not found either in the ovary or other primary sites. From these pathological findings, we concluded that the disease was an intraepithelial adenocarcinoma, possibly derived from multipotential cells in squamous epithelium of ovarian mature cystic teratoma. This is the first reported case, to our knowledge, of extramammary Paget's disease arising in mature cystic teratoma of the ovary.

Adenocarcinoma↗
PubMed1991

Myelodysplastic syndrome with myelofibrosis: myelodysplastic syndrome as a major primary disorder for acute myelofibrosis.

Seven cases of myelodysplastic syndrome with myelofibrosis, which is defined using the following criteria: (1) pancytopenia with less than 5% blasts in the peripheral blood; (2) minimal or no splenomegaly; (3) myelofibrosis with cellular marrow; (4) absence of diffuse proliferation of blasts in the bone marrow; and (5) presence of myelodysplastic features of bone marrow or peripheral blood cells, are presented. They were in the range of 52-82 years old and consisted of 3 males and 4 females. Six out of 7 cases developed into acute leukaemia after 5 to 8 months from the onset and died from between 2 weeks to 8 months from the evolution to leukaemia. The type of leukaemia was acute myeloblastic in 3 patients, and acute myelo-megakaryoblastic in 3 patients. Another patient died of severe hepatic injury after 5 months from the onset of the disease. These findings revealed that the complication of myelofibrosis in the patients with myelodysplastic syndrome was an indicative sign of rapid progression to overt leukaemia or otherwise poor prognosis for survival. In addition myelodysplastic syndrome is thought to be major primary disorder for acute myelofibrosis. Myelodysplastic syndrome with myelofibrosis is closely associated with the neoplastic proliferation of megakaryoblasts in a considerable number of patients.

Acute Disease↗
PubMed1991

Transvaginal color and pulsed Doppler ultrasound evidence of hemodynamics of the female pelvis.

Transvaginal color and pulsed Doppler ultrasound examinations were made on 40 patients to assess hemodynamics in the pelvis. Use of a special probe for transvaginal scanning led to superb simultaneous visualization of structures and blood flow, and we noted various events, even in the small, deep and/or peripheral vessels. Some but not all of the observations were in agreement with the results obtained using transabdominal color and pulsed Doppler ultrasound. We propose that transvaginal color and pulsed Doppler ultrasound be considered for routine use to determine physiological and pathological events in the female pelvis.

Color↗
PubMed1991

Anti-5-hydroxytryptamine3 effect of galanolactone, diterpenoid isolated from ginger.

It has been reported that an acetone extract of ginger and its fractions have anti-5-HT (5-hydroxytryptamine; serotonin) effects. In the present study, guinea pig ileum, rat stomach fundus and rabbit aortic strips are used in order to determine the constituents of fraction 2 which are responsible for anti-5-HT effect and to examine their pharmacological properties. The analysis of fraction 2-3 indicated that galanolactone, a diterpenoid, is one of the active constituents. In guinea pig ileum, galanolactone inhibited contractile responses to 5-HT with a pIC50 value 4.93. pIC50 value of galanolactone against the response to 2-methyl-5-HT, a selective 5-HT3 agonist, in the presence of methysergide at 1 x 10(-5) M was 5.10. pIC50 values of ICS 205-930, a selective 5-HT3 antagonist, were 5.30 and 7.49, respectively. The concentration-response curve of 5-HT was shown as a biphasic curve and galanolactone caused a selective shift to the right of the second phase. In the same preparations, the pIC50 value of galanolactone and ICS 205-930 against the response to carbamylcholine (CCh) was 4.45 and 4.46. The inhibitory effect of galanolactone on the 5-HT response in the stomach fundus and aortic strips was less than that in the ileum. In addition, in the thoracic aorta precontracted with 50 mM K+, the relaxing effect of galanolactone was about 1/10 of that of papaverine. These results suggest that the anti-5-HT effect of galanolactone, a diterpenoid isolated from ginger, is related to antagonism of 5-HT3 receptors.

Animals↗
PubMed1991

Functional reinnervation of carotid artery by implanted preganglionic trunk in the cat.

The preganglionic trunk of the superior cervical ganglion was implanted chronically into the carotid artery. A helical strip of the carotid artery with nerve was prepared, and electrical stimulation of the nerve caused a definite contraction. Part of the contraction was attenuated by phentolamine, and the remaining part of the contraction was nearly abolished by tubocurarine but not by hexamethonium and atropine. The present results clearly demonstrate that the carotid artery is reinnervated by preganglionic cholinergic fibers.

Animals↗