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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 721 records · Page 40Linked to original sources
PubMed1989

Calcitonin gene-related peptide and vasodilator nerves in large cerebral arteries of cats.

Calcitonin gene-related peptide's (CGRP) role(s) was examined in the transmural nerve stimulation (TNS)-induced vasodilator response of the large cerebral arteries of the cat in vitro. Numerous CGRP-like immunoreactive nerves were demonstrated to be present in the adventitial layer of the middle cerebral, anterior communicating and basilar arteries of the cat. An electron microscopic study revealed that immunoreactive material was contained in not only nerve axons but also in the button-like structures, i.e., varicosities, which were located close to smooth muscle cells. Exogenously applied CGRP induced a dose-dependent vasodilator response which was independent of the presence of endothelial cells and of nerve components. Nerve stimulation elicited transient hyperpolarization, i.e., inhibitory junction potential, which was of nonadrenergic, noncholinergic origin. Likewise, CGRP produced hyperpolarization of smooth muscle cells. After incubation of the tissue with capsaicin in vitro, the intensity of the CGRP-like immunoreactivity diminished greatly. The TNS-induced vasodilator response and inhibitory junction potentials were also attenuated after the incubation with capsaicin. These results suggest that CGRP is involved in the TNS-induced vasodilator response of the large cerebral arteries of the cat.

Animals↗
PubMed1989

Involvement of calcitonin gene-related peptide in the positive chronotropic and inotropic effects of piperine and development of cross-tachyphylaxis between piperine and capsaicin in the isolated rat atria.

Piperine as well as capsaicin showed positive chronotropic and inotropic effects in the isolated spontaneously beating right atria and electrically driven left atria of rats, respectively. The responses to piperine were not affected by the presence of the antagonists to norepinephrine, acetylcholine, histamine and serotonin. However, once the tissue was pretreated with piperine or capsaicin, the response to subsequent application of piperine was reduced significantly. Both positive chronotropic and inotropic effects of capsaicin were also attenuated after the tissue was treated with piperine or capsaicin. Thus, not only a tachyphylaxis to either piperine or capsaicin itself but also a cross-tachyphylaxis between piperine and capsaicin developed. Nonadrenergic noncholinergic calcitonin gene-related peptide (CGRP)-like immunoreactive nerves were distributed in the muscle layers of both atria. CGRP-like immunoreactivity was depleted considerably by treatment of the tissue with piperine or capsaicin. When endogenous CGRP was depleted, although the positive chronotropic and inotropic effects of piperine and capsaicin were abolished, the effects of CGRP and isoproterenol were not affected. These results indicate that both piperine and capsaicin cause positive chronotropic and inotropic responses by releasing CGRP from nonadrenergic noncholinergic nerves, and that the development of cross-tachyphylaxis between piperine and capsaicin is due to the depletion of endogenous CGRP.

Alkaloids↗
PubMed1989

[Usefulness of intracranial pressure monitoring and EEG analysis in a child with acute encephalitis].

The usefulness of continuous intracranial pressure (ICP) monitoring and the correlation between ICP and electroencephalographic findings were investigated in a 6-year-old boy with acute encephalitis. On admission he was comatose in a decerebrate posture. ICP was continuously monitored by the epidural transducer and controlled with hyperventilation, fluid restriction and administration of mannitol, glycerol and pentobarbital to keep below 20 mm Hg. The inotropic agents such as dopamine and dobutamine were also given to maintain the cerebral perfusion pressure (CPP) at 50 mm Hg or greater. At the same time with ICP monitoring, EEG records were obtained with scalp electrodes at monopolar T3-A1 and T4-A2 regions according to the 10-20 international system on an analog tape simultaneously with a data recorder. The records were digitized at 50 samples/sec, and the high-order auto-regressive (AR) power spectrum was calculated with a minicomputer PFU-1200 (Fujitsu Co Ltd.). At pressures greater than 25 mm Hg in ICP, the total power of the high-order AR activity of EEG was apparently decreased. The results indicated that the AR power spectral analysis of EEG is sensitive method for obtaining valuable information regarding the electrical brain activity and intracranial pressure.

Acute Disease↗
PubMed1989

["My hand" sign associated with tactile extinction in two patients with callosal lesion].

Two patients with "my hand" sign in association with tactile extinction from callosal lesion, one due to left anterior cerebral artery occlusion, the other due to right anterior cerebral artery aneurysm rupture, were reported. The examination of "my hand" sign was performed with the methods proposed by Brion et al. Our patients correctly responded when they grasped their own or the examiner's thumb with their left hand. But they replied "my finger"when they grasped not only their own but also the examiner's thumb with their right hand. Left tactile extinction was observed after a routine extinction test in one patient, and it was observed in the other after the following method: both patient's index fingers were disposed in his midline position. In these methods of extinction test, they made errors in saying "right" when both fingers were touched simultaneously. However, they said "both" when their right index finger alone was touched (synchiria) during an extinction test using the following method: both index fingers of patients were approached by examiner to touch each other or for one of them to touch the examiner's finger. When they were asked whose finger they touched in this method (whose finger test), they made the same errors as seen in "my hand" sign test. These test results suggest that there is a common underlying mechanism in the "my hand" sign and extinction, because the sense of double stimulations felt when only one stimulation is given (synchiria), is a possible explanation for the "my hand" sign and the pathogenesis of synchiria appears to be related to extinction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Intra-arterial infusion chemotherapy with [Sar1, Ile8] angiotensin II in bladder cancer].

Twenty patients with bladder cancer were treated with intra-arterial infusion chemotherapy using CDDP and ADM in combination with [Sar1, Ile8] angiotensin II. A catheter was introduced into internal iliac artery by Seldinger's technique, and 100 mg of CDDP, 50 mg of ADM and 1 mg of [Sar1, Ile8] angiotensin II were infused through the catheter for 40 minutes. CR was observed in 8 of 20 patients. PR in 11 and NC in 1. Therefore, the response rate (CR + PR) was 95% (19/20). Side effects were generally mild and consisted of leukopenia, nausea, vomiting, diarrhea, alopecia, skin pigmentation and headache. Catheter-related complications were not observed. This study demonstrated that intra-arterial infusion chemotherapy with CDDP and ADM in combination with [Sar1, Ile8] angiotensin II was extremely effective in treating patients with bladder cancer.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1989

[Developmental characteristics of the alpha waves of EEG in normal healthy children].

The records of waking state electroencephalography (EEG) of 1,340 normal children aged from 3 to 12 years were subjected to analysis using an autoregressive model. The results were summarized as follows. (1) 6,814 components of second-order activities were obtained through component analysis of the 1,218 EEG records. The frequency polygons of damping frequency of the second-order component waves verified several modes, each of which was enhanced in the eight frequency ranges. (2) The average percent-power of the alpha-1 waves decreased with increasing ages from 3 years, whereas that of the alpha-2 waves increased. That of the alpha-3 waves showed no change with ages. (3) The average damping times of alpha-2 waves increased with increasing ages. (4) Dominancy in frequency showed a course of two step increments at 3-6 and 10 years of age. The former was chiefly due to the increase in the alpha-1 wave and the latter in the alpha-2 wave. There were no significant increases of alpha-3 waves. (5) By means of EEG pattern discrimination, the differences in alpha components among different age groups were obtained as generalized (Maharanobis') distances. The alpha-1 activity showed a significant difference in amount between the age group of 3-6 years and the other age groups. The alpha-2 activity showed a significant difference in amount between the age group of 10 years and the other age groups. (6) The development of brain activity proceeds faster in the posterior areas and relatively slower in the central areas.

Aging↗
PubMed1989

[Developmental characteristics of the beta waves of EEG in normal healthy children].

By the use of an autoregressive (AR) model, development of beta-waves in quantitative EEG parameters was studied in 1,340 normal children aged from 3 to 12 years. The results were summarized as follows. The beta band(13.5-25 Hz) was divided into three frequency ranges; beta-1(13.5-17.4 Hz), beta-2(17.5-21.4 Hz) and beta-3 (21.5-25 Hz) waves. The average power and percent-power of the beta-1 and beta-2 waves increased with advancing age, whereas these of the beta-3 wave showed no change with advancing age. By means of EEG pattern discrimination, critical period of beta band in the developing EEG was observed at the age of 4 years in frontal region, 10 years in central region and 3 to 7 years in occipital region. Those results suggest that the development of beta activity may be faster in frontal, occipital areas and relatively slower in central area.

Aging↗
PubMed1989

[A case of Cockayne's syndrome with clinical symptoms in the neonatal period].

A 2-year-old boy with Cockayne's syndrome was reported. The patient was noticed to have poor sucking and poor weight gain from the neonatal period and showed poor psychomotor development after 4 months of age and failed to gain weight after 8 months of age. At 11 months of age, CT revealed brain atrophy and calcification in the basal ganglia, the cerebral white matter and the cerebral cortex. At this time, the peripheral neuropathy was also detected. At 22 months of age, CT showed marked brain atrophy and diffuse intracranial calcification with the cerebellar calcification.

Child, Preschool↗
PubMed1989

[Lateral inferior pontine syndrome: a case report].

The patient, a man aged 57, was admitted to our clinic on May 1, 1987, because of severe vertigo and unsteadiness in standing. Since the age of 55 he had been suffered from hypertension and atrial fibrillation. In September, 1986, he experienced vertigo but recovered soon without therapy. On April 25, 1987, while working, he noticed severe vertigo, nausea and vomiting. He was admitted to a hospital, and then transferred to our clinic. On admission, he was alert and the mentality was normal. Slight ptosis abducent nerve paresis, hypalgesia on the forehead, nose and cheek, facial paresis of peripheral type and hypacusis were detected on the left side. No anisocoria was observed. Sweating was impaired over the left side of the face. Elevation of the soft palate was limited on the left side and the tongue deviated to the left on protrusion. Dysarthria was detected. Though there was no muscular weakness in the extremities, incoordination and dysmetria were noted in the left arm and leg. He could not stand up because of vertigo and unsteadiness. There was no sensory disturbance in the trunk and extremities. Deep tendon reflexes were well elicited and no pathological reflex was observed. These clinical manifestations, except for the ipsilateral palatal and lingual disturbances, were typical of the lateral inferior pontine syndrome caused by occlusion of anterior inferior cerebellar artery, and the lesion was clearly demonstrated by horizontal and coronal MRI. The palatal and lingual disturbances might be due to the involvements of the corticobulbar tracts of the 10th and 12th nerves after the fibers had decussated.

Arterial Occlusive Diseases↗
PubMed1988

Structure-activity relationships of endothelin: importance of the C-terminal moiety.

The vasoconstrictor activities of various forms of derivatives of endothelin (ET) were characterized in vitro by measuring the contraction of porcine coronary artery strips. The removal of the C-terminal Trp21 reduced the molar potency of the peptide by nearly 3 orders of magnitude. The removal of amino acid residues from the C-terminus of ET(1-20) further attenuated the activity. Replacement of Trp21 with D-Trp, reduction and carboxamidomethylation of the four Cys residues, or cleavage at Lys9 by lysyl endopeptidase all lowered the potency approximately 200 fold. While both native ET and [D-Trp21]ET induced a very slow and sustained vasoconstriction, the other derivatives of ET listed above showed a much more rapid kinetics of vasoconstriction. These results indicate that the C-terminal Trp of ET is especially important for the potent and extremely long-lasting vasoconstrictor activity characteristic to ET.

Animals↗
PubMed1988

Effects of intracoronary injection of acetylcholine on coronary arterial hemodynamics and diameter.

To examine the effects of intracoronary injection of acetylcholine on coronary blood flow and on coronary arterial diameter in humans, acetylcholine was injected into the left coronary artery in 32 adult patients (21 men and 11 women with a mean age of 54 years, range 37 to 65) with normal or almost normal coronary arteriographic findings. Patients with angina pectoris, myocardial infarction and severe cardiac diseases were excluded. Temporary right ventricular pacing was set at a rate of 60 beats/min to prevent transient bradyarrhythmias during intracoronary injection of acetylcholine. Measurements of coronary sinus blood flow and coronary vascular resistance and quantification of coronary arterial diameters using a computer-assisted technique were performed before and after each injection of 20, 50 and 100 micrograms of acetylcholine. Significant increase in coronary sinus blood flow and significant decrease in coronary vascular resistance occurred after intracoronary injection of acetylcholine. In contrast, mean diameter of normal epicardial coronary artery tended to decrease and that of irregular epicardial coronary artery decreased significantly after intracoronary injection of acetylcholine. Intracoronary injection of acetylcholine increases coronary blood flow, suggesting vasodilation in the coronary arteriolar bed, while it induces vasoconstriction in most of epicardial coronary arteries in adult humans.

Acetylcholine↗
PubMed1988

Calcitonin gene-related peptide acts as a novel vasodilator neurotransmitter in mesenteric resistance vessels of the rat.

Systemic blood pressure is controlled by changes in the resistance of the peripheral vascular bed for example in the mesenteric blood vessels. The tone of peripheral blood vessels is primarily maintained by sympathetic vasoconstrictor nerves. Although vasodilator innervation has been identified in certain isolated elastic arteries, it is not known whether vasodilator nerves contribute to the regulation of the peripheral resistance vessels. We present pharmacological evidence for the existence of nonadrenergic, noncholinergic (NANC) vasodilator nerves in the mesenteric resistance vessel of the rat and that the resistance is controlled by not only sympathetic vasoconstrictor nerves but also NANC vasodilator nerves. We also show that the neurogenic vasodilation was selectively abolished by depleting endogenous calcitonin gene-related peptide (CGRP), a potent vasodilator neuropeptide, from perivascular nerves. This indicates that CGRP is a novel vasodilator neurotransmitter and may play a role in control of the total peripheral resistance of systemic circulation through a local reflex mechanism.

Animals↗
PubMed1988

Effects of piperine on calcitonin gene-related peptide (CGRP)-containing nerves in the isolated rat atria.

Piperine, a major pungent agent of black peppers, induced both positive chronotropic and inotropic responses in the isolated atria of rats. These responses were not blocked by various antagonists but exhibited rapid tachyphylaxis. After exposure to piperine in vitro, endogenous calcitonin gene-related peptide (CGRP) was profoundly depleted from intracardiac nerves. These results suggest that piperine releases endogenous CGRP from intracardiac non-adrenergic non-cholinergic nerves and that released CGRP exerts positive chronotropic and inotropic effects.

Alkaloids↗
PubMed1988

Positive inotropic effects and receptors of calcitonin gene-related peptide (CGRP) in porcine ventricular muscles.

Calcitonin gene-related peptide (CGRP) in porcine ventricular muscles. positive inotropic effects in the isolated, electrically driven false tendon of the porcine heart. Specific CGRP-binding sites were present in solubilized membrane fractions; the dissociation constant (Kd) and the maximum binding (Bmax) were 50.4 pM and 180 fmol/mg protein, respectively. SDS-PAGE analysis of CGRP-binding sites revealed the molecular mass of 70 K and 120 K. Few CGRP-like immunoreactive nerves were present in the ventricular muscle layer. These results indicate that CGRP activates specific receptor sites on the ventricular muscles and causes positive inotropic responses. CGRP receptors in ventricles are likely to be activated by circulating CGRP.

Animals↗
PubMed1988

A novel potent vasoconstrictor peptide produced by vascular endothelial cells.

An endothelium-derived 21-residue vasoconstrictor peptide, endothelin, has been isolated, and shown to be one of the most potent vasoconstrictors known. Cloning and sequencing of preproendothelin complementary DNA shows that mature endothelin is generated through an unusual proteolytic processing, and regional homologies to a group of neurotoxins suggest that endothelin is an endogenous modulator of voltage-dependent ion channels. Expression of the endothelin gene is regulated by several vasoactive agents, indicating the existence of a novel cardiovascular control system.

Amino Acid Sequence↗