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Biomedical subjects

K Ando

Publications and source records attributed to K Ando.

At least 595 records · Page 33Linked to original sources
PubMed1987

Presence of the atrial natriuretic peptide in human cerebrospinal fluid.

Using a highly sensitive and specific radioimmunoassay (RIA) for detection of the atrial natriuretic peptide (ANP), the presence of alpha-human ANP (alpha-hANP) in human cerebrospinal fluid (CSF) was confirmed. Its concentration in CSF, 3.6 +/- 2.3 pg/ml, n = 16, mean +/- SD, was remarkably lower than that in the plasma (161.8 +/- 157.4, p less than 0.0001). The regression coefficient between these concentrations was 0.320 (p = ns). Gel permeation chromatography conducted in conjunction with RIA indicated ANP in CSF to be eluted at the position of a low molecular weight form corresponding to alpha-hANP. No high molecular weight form could be detected. But in the plasma, both low and high molecular forms were found to be present. It is thus evident that ANP is present in human CSF and its origin may possibly be the brain and not the atrium.

Adult↗
PubMed1987

Purification of sarcotoxin II, antibacterial proteins of Sarcophaga peregrina (flesh fly) larvae.

Three antibacterial proteins with almost identical primary structures termed sarcotoxin IIA, IIB, and IIC were purified to homogeneity from the hemolymph of third instar larvae of Sarcophaga peregrina. The molecular masses of these proteins were about 24,000. These proteins were found to have common antigenicity, and antibody against sarcotoxin IIA cross-reacted with sarcotoxin IIB and IIC. Radioimmunoassay using this antibody showed that these proteins are induced in the hemolymph in response to injury of the larval body wall.

Amino Acids↗
PubMed1987

Simultaneous determination of catechols in thalamic slices with liquid chromatography/electrochemistry.

A method was developed for the simultaneous determination of dopamine (DA), epinephrine (E), norepinephrine (NE), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxyphenylglycol (MHPG), as well as L-3,4-dihydroxyphenylalanine (L-DOPA) with liquid chromatography (LC) using electrochemical (EC) detection. With a ODS column and a mobile phase consisting of a sodium acetate-citrate with heptasulfonic acid, this method was applied on simultaneous determination of catechols released from thalamic slices of ddY mouse. The pretreatment of the bathing medium required only centrifugation, and the supernatant was injected directly into the LCEC system. The high potassium stimulation of catecholaminergically innervated thalamic slices led to increase in the levels of DA, NE, DOPAC and MHPG, especially of NE, but not that of L-DOPA itself. In the present study, we designed to make simultaneous determination of catechols released from thalamic slices for estimation of the physiological status of catecholaminergic neuronal activity.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Suppression of hypertriglyceridemia of Ehrlich carcinoma-bearing mice by an antibiotic, ascofuranone.

Ehrlich ascites carcinoma-bearing mice exhibit hypertriglyceridemia. An antitumor antibiotic, ascofuranone, suppressed tumor-induced hypertriglyceridemia when administered i.p. even when no evident antitumor activity was observed without affecting the levels of free fatty acids, phospholipids, cholesterol, glucose, and total protein in plasma. Ascofuranone did not reduce plasma triglycerides of normal mice. Insulin and clofibrate, known modifiers of lipid metabolism, showed no significant suppression. Ascofuranone is also effective on solid tumor-induced hypertriglyceridemia. Another notable change of metabolism affected by tumor-bearing in the early stage where hypertriglyceridemia has not yet fully progressed is hypoglycemia. Although ascofuranone did not affect hypoglycemia, the suppressive effect on hypertriglyceridemia was more evident when ascofuranone was administered in the early stage than in the later stage. These results suggest that ascofuranone suppresses hypertriglyceridemia by specifically affecting the changes of host metabolism which is induced in the early stage of tumor bearing.

Animals↗
PubMed1987

Intraclonal diversity of fibrosarcoma cells for the production of macrophage colony-stimulating factor and granulocyte colony-stimulating factor.

A new cell line was established from fibrosarcoma that had spontaneously developed in a mouse. The cells were maintained growing in culture for two years and constantly produced both macrophage colony-stimulating factor (M-CSF) and granulocyte colony-stimulating factor (G-CSF). Cloning of the cells by anchorage-independent colony formation gave subclones showing the activity of producing M-CSF and G-CSF in different proportions, whereas no subclone produced G-CSF without producing M-CSF simultaneously. Recloning of the bipotential subclones again gave clonal derivatives producing two types of CSF in various proportions. The observed heterogeneity of the cloned cells seems to be an epigenetic phenomenon, because the cells resumed the G-CSF producing activity in the absence of cell proliferation. After equilibrium was achieved, all of the subclones produced both M-CSF and G-CSF nearly in equal proportions. Tumorigenic and leukocytosis-inducing activity of the cloned cells was nearly comparable with the activity of the original tumor cells.

Animals↗
PubMed1987

The effects of ethanol on eye tracking in rhesus monkeys and humans.

The effects of ethanol on eye tracking function were compared in rhesus monkeys and humans using a similar experimental procedure. In Experiment 1, 3 rhesus monkeys were trained to visually track a projected image of a disk that oscillated sinusoidally along a horizontal plane on a screen. This training was accomplished using a procedure in which responses on a lever resulted in the delivery of water when the central area of the projected disk image was dimmed for a brief period. Intragastric administrations of ethanol at doses of 0.25 to 2 g/kg were tested during one-day test sessions using a cumulative dose procedure. Pursuit eye movements were disrupted at doses of 0.5 g/kg while lever pressing behavior was not disrupted until a dose of 2 g/kg was reached. In Experiment 2, pursuit eye movements of 6 humans were not disrupted when ethanol was given orally at cumulative doses of 0.25 to 1 g/kg, while microswitch pressing behavior was disrupted in some of the subjects at a dose of 0.5 g/kg. Blood ethanol levels increased in a dose-dependent manner in both species with higher levels in humans than in monkeys. The dose dependent effects observed in both species and qualitative similarities in some of the effects such as saccadic pursuit eye movements suggest that the eye tracking method employing monkeys is useful for predicting drug effects on sensory motor function in humans.

Adult↗
PubMed1987

Specific biodetection of B16 mouse melanoma in vivo by syngeneic monoclonal antibody.

The specific detection of tumors in vivo using a radiolabeled syngeneic monoclonal antibody made by fusion of P3U1 (BALB/c myeloma cells) and C57BL/6 spleen cells primed with syngeneic B16 melanoma cells was investigated by color imaging, autoradiography, and biodistribution. The radiolabeled antimelanoma antibody specifically accumulated only in the tumor lesions, whereas no radioactivity was observed in normal tissues or organs. The distribution patterns of the radioactive antibody in the tumor lesions depended on the sizes of the tumor. Almost the entire region of the small metastatic tumor in lymph nodes was labeled, whereas the radioactive antibody was irregularly localized mainly in the center of the medium-sized tumor. However, only the peripheral region of the large primary tumor was labeled. The highest uptake of radioactivity (tumor:blood ratio) was observed in the small lymph node metastatic tumor lesions rather than in the large primary tumor. Furthermore, high resolution color imaging of B16 melanoma was also obtained by using 125I-labeled monoclonal antibody. Tumor location was specifically visible without subtraction or enhancement methods 3-5 days after injection of the radiolabeled antibody.

Animals↗
PubMed1987

Capsaicin enhances the non-adrenergic twitch response of rat vas deferens.

1 Capsaicin (Cap) enhanced the twitch response of the epididymal and prostatic portions of rat vas deferens induced by field stimulation at 0.1 Hz. The effect of Cap was reproducible and showed no desensitization. 2 Prazosin, and pretreatment with reserpine or Cap did not affect the potentiating effect of Cap, whereas pretreatment with 6-hydroxydopamine abolished the action of Cap. 3 Cap tended to attenuate the contractions induced by noradrenaline, tyramine and ATP. 4 Like Cap, substance K and substance P augmented the twitch response without causing desensitization, but their effects differed somewhat from that of Cap. Calcitonin gene-related peptide inhibited the twitch response. 5 These results suggest that Cap enhances a stimulation-induced, prazosin-resistant non-adrenergic twitch response of rat vas deferens through an as yet undefined prejunctional mechanism. This mechanism is possibly mediated by some peptide released in response to Cap from sensory neurones, which in turn acts on sympathetic nerves and increases stimulation-induced release of a mediator or cotransmitter responsible for the non-adrenergic twitch response. However, the possibility that Cap has a direct action on sympathetic nerves cannot be ruled out.

Animals↗
PubMed1987

Effects of increased adrenomedullary activity and taurine in young patients with borderline hypertension.

Recent studies showed that taurine, a sulphonic amino acid, could decrease blood pressure and increase sympathoadrenal tone in DoCA-salt-treated hypertensive rats. To determine whether taurine exerts its antihypertensive action in man in a similar fashion, we studied the effect of oral administration of taurine (6 g for 7 days) on blood pressure and plasma catecholamines in 19 young patients with borderline hypertension in a double-blind, placebo-controlled fashion. Systolic blood pressure in the 10 patients who were treated with taurine decreased by 9.0 +/- 2.9 mm Hg (mean +/- SE; p less than .05 by paired t test), compared with a 2.7 +/- 2.3 mm Hg decrease (NS) in the nine patients treated with placebo and diastolic blood pressure in the taurine-treated patients decreased by 4.1 +/- 1.7 mm Hg (p less than .05) compared with 1.2 +/- 3.0 mm Hg (NS) in the placebo-treated subjects. In the patients receiving taurine plasma epinephrine (E) decreased significantly, with a negligible decrease in plasma norepinephrine (NE). The effect of taurine on plasma catecholamines and the response of plasma E after the stimulation with glucagon was also studied in 12 borderline hypertensive and nine age-matched normotensive subjects. Basal plasma E was significantly higher in borderline hypertensive than in normal subjects, but basal plasma NE did not differ in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗
PubMed1987

Role of sympathetic nervous system in hypotensive action of taurine in DOCA-salt rats.

We tested the hypothesis that the antihypertensive effects of dietary taurine supplementation in deoxycorticosterone acetate (DOCA)-salt rats may be attributed to the suppression of sympathetic nervous system activity. In uninephrectomized rats treated with DOCA while receiving 1% NaCl solution for 2 weeks, systolic blood pressure was significantly increased as compared with that in control rats treated with vehicle suspension and tap water. Sympathetic nervous system activity was assessed by tissue norepinephrine turnover, which was determined from the rate of decline of tissue norepinephrine concentration after the administration of alpha-methyl-p-tyrosine, a potent inhibitor of the rate-limiting step of catecholamine synthesis. Cardiac and splenic norepinephrine turnover during either normal conditions or cold exposure (4 degrees C, 8 hours) were markedly increased in DOCA-salt rats as compared with control rats. Also, DOCA-salt rats had increased depressor response to hexamethonium bromide, a ganglion blocker. In contrast, supplementation of 1% taurine in DOCA-salt rats attenuated the development of the hypertension associated with the normalization of both the increased depressor response to ganglionic blockade and the accelerated cardiac and splenic norepinephrine turnover during either normal conditions or cold exposure. Taurine supplementation in control rats, however, had no effect on blood pressure or norepinephrine turnover during cold exposure. These results suggest that taurine supplementation suppresses sympathetic overactivity in DOCA-salt rats, thus leading to inhibition of the development of hypertension.

Animals↗
PubMed1987

Vasodilatory actions of alpha-human atrial natriuretic peptide and high Ca2+ effects in normal man.

To study vascular actions of synthetic alpha-human atrial natriuretic polypeptide (alpha hANP) in man, forearm blood flow (FBF) was measured by strain-gauge plethysmograph during the continuous infusion of 100 ng/min alpha hANP dissolved in 5% dextrose into the brachial artery in healthy subjects. alpha hANP increased FBF, with the concomitant increase in ipsilateral limb venous plasma concentrations of alpha hANP. Overall, there was a significant linear correlation between the decrements of ipsilateral forearm vascular resistance (FVR) during infusions of alpha hANP and initial FVR levels (r = -0.883, P less than 0.01). Moreover, alpha hANP, at the stepwise increasing doses of 20, 100, and 500 ng/min, increased FBF in a dose-related fashion: alpha hANP elicits a concentration-dependent vasodilation of forearm vascular beds. Concomitantly, infusions of alpha hANP caused a dose-dependent increase in ipsilateral limb venous plasma cyclic guanosine monophosphate (cyclic GMP). Overall, there were direct correlations of FBF either to ipsilateral venous plasma alpha hANP (r = 0.724, P less than 0.01) or to cyclic GMP concentrations (r = 0.637, P less than 0.01). Subsequently, isoosmolar CaCl2 solution was infused into the same brachial artery at a rate of 0.09 meq/min, and then, with a 2.5 +/- 0.2-mg/dl increase in ipsilateral venous serum calcium concentrations the incremental responses of both FBF and plasma cyclic GMP to alpha hANP were severely blunted. There was also a significant positive linear correlation between FBF and venous plasma cyclic GMP during infusions of alpha hANP with the simultaneous administration of CaCl2 (r = 0.807, P less than 0.01). Finally, the addition of CaCl2 infusion did not change the slope of the regression line of the FBF-plasma cyclic GMP relationship during infusions of alpha hANP. Evidence presented suggests that alpha hANP acts directly on the forearm vascular beds in man, eliciting its vascular relaxant effect, possibly by increasing cellular levels of cyclic GMP. Moreover, modest elevations of serum calcium inhibit the alpha hANP-dependent vasodilation, possibly through the suppression of cyclic GMP activation.

Adolescent↗
PubMed1987

Galactorrhea in subclinical hypothyroidism.

Galactorrhea was found in 5 patients with subclinical hypothyroidism. The galactorrhea consisted of the discharge of a few drops of milk only under pressure. Serum T4 was in the lower level of the normal range, but serum T3 was normal (T4: 6.3 +/- 1.2 micrograms/dl, T3: 113 +/- 7 ng/dl). Basal serum TSH and PRL were slightly increased only in 2 and 1 cases, respectively. The PRL responses to TRH stimulation were exaggerated in all cases, although the basal levels were normal. An enlarged pituitary gland was observed in 1 patient by means of CT scanning. All patients were treated by T4 replacement. In serial TRH tests during the T4 replacement therapy, the PRL response was still increased even when the TSH response was normalized. Galactorrhea disappeared when the patients were treated with an increased dose of T4 (150-200 micrograms/day). Recurrence of galactorrhea was not observed even though replacement dose of T4 was later decreased to 100 micrograms/day in 4 cases. In patients with galactorrhea of unknown origin, subclinical hypothyroidism should not be ruled out even when their serum T4, T3, TSH and PRL are in the normal range. The TRH stimulation test is necessary to detect an exaggerated PRL response, as the cause of the galactorrhea. To differentiate this from pituitary microadenoma, observation of the effects of T4 replacement therapy on galactorrhea is essential.

Adult↗
PubMed1987

[Fundamental study on ataxic mice (wriggle mouse Sagami)].

Wriggle mouse Sagami (WMS), a newly discovered BALB/C mouse strain, is characterized by its locomotor instability, abnormal gait pattern and neck wriggling. Although the growth of WMS mice is delayed, compared with normal BALB/C mice, the brain size corresponds to the relatively smaller body weight. In gross or histological examinations no local atrophy appears in the cerebrum, cerebellum, brain stem or spinal cord. The c-GMP level in the WMS cerebellum is decreased, but the c-AMP level is normal. The ataxic gait is not improved significantly by the administration of thyrotropin releasing hormone (TRH). These results indicate that the mechanism inducing ataxia and abnormal gait pattern in WMS may be different from those in other genetically-determined ataxic mice, e. g., Rolling mouse Nagaya (RMN), PCD, Staggerer and Reeler.

Animals↗
PubMed1987

Macrophage-specific effect on lipid metabolism by an antibiotic, ascofuranone.

Ascofuranone (AF) enhanced glucose consumption of splenocytes and macrophages, while it enhanced incorporation of [14C]acetate into macrophages but not into splenocytes. When using tumor cell lines, it inhibited the incorporation of [14C]acetate into lymphoma cell lines, YAC-1 and P388, and a thymoma, L5178Y, while it stimulated that into P388D1, which is derived from P388 and has macrophage-like characteristics. Incorporation of [14C]acetate into a mammary carcinoma FM3A was also stimulated by AF. In contrast, AF stimulated uptake of methylglucose in all cell lines tested. The effect of AF was further studied using mouse myeloid leukemia, M1 cells. AF slightly stimulated the incorporation of [14C]acetate into undifferentiated M1 cells, and strongly stimulated that of hydrocortisone-differentiated M1 cells. In contrast, AF suppressed the incorporation of [14C]acetate into retinoic acid-differentiated M1 cells. Glucose consumption of these three types of M1 cells was all stimulated. From these results, we conclude that AF specifically stimulates the incorporation of [14C]acetate into macrophages while it generally stimulates glucose uptake of the cells.

Acetates↗
PubMed1987

[Chemical radioprotectors].

Basic mechanisms of radioprotection and clinical applicability of radioprotectors for low-and high-LET radiotherapy were reviewed and discussed here. Chemical radioprotectors are able to inhibit indirect radiation damage, to repair direct and indirect damage once they occur, and to facilitate the recovery of damaged cells on depleted cell populations. The vast majority of radioprotective agents that have been developed and tested are the aminothiols. WR-2721 or ethiofos represents a significant improvement in effectiveness, potency and reduction of toxicity over the early radioprotectors. WR-151327 provided substantial protection against neutron irradiation. Dose modification factors after single doses of cyclotron neutrons were 1.5 for both early and late skin damage and 1.5-2.4 for late muscle damage.

Amifostine↗