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Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 955 records · Page 53Linked to original sources
PubMed1988

Are the cardiovascular effects of gentamicin similar to those of calcium antagonists?

Cardiac and coronary vasodilator effects of gentamicin (GM) were investigated in isolated, blood-perfused papillary muscle, sino-atrial (SA) node and atrioventricular (AV) node preparations of dogs. GM (0.3-100 mumol) was injected intraarterially. GM produced an increase in coronary blood flow in all preparations. In paced papillary muscle preparations, GM reduced the force of contraction. In spontaneously beating papillary muscle preparations, GM decreased the rate of automaticity and the force of contraction. In SA node preparations, GM decreased the sinus rate. In AV node preparations, GM injected into the posterior septal artery (which supplies the AV node) increased AV conduction time and in large doses, produced third-degree AV block. In the same preparations, GM in large doses injected into the anterior septal artery (which supplies the His-Purkinje-ventricular system) prolonged AV conduction time (i.e., intraventricular conduction time) and reduced the amplitude of ventricular bipolar electrograms. The order of potencies of GM on the above cardiovascular variables is as follows: Coronary blood flow greater than or equal to ventricular muscle contraction greater than ventricular automaticity greater than SA nodal automaticity greater than AV nodal conduction greater than intraventricular conduction. This cardiovascular profile is different from those of organic calcium-antagonists, but rather similar to that of manganese ions, reflecting its own mechanism of action.

Animals↗
PubMed1988

Exacerbation of indomethacin-induced gastric ulceration by systemically administered GABA in rats: possible involvement of peripheral GABA receptors.

Effects of systemically administered gamma-aminobutyric acid (GABA) on indomethacin-induced gastric ulceration were studied in rats. Orally administered GABA significantly exacerbated the ulceration in a dose-dependent manner, although GABA per se had no ulcerogenic activity. The exacerbation was restored by GABA receptor antagonists, bicuculline methiodide, picrotoxin and pentylenetetrazol. Pretreatment with atropine sulfate antagonized the exacerbating effect of GABA on indomethacin-induced ulceration. 3-Amino-1-propanesulfonic acid, but not glycine, taurine or beta-alanine, mimicked the effect of GABA on the ulceration, which was inhibited by picrotoxin. Muscimol and (-)-baclofen could not potentiate the ulceration. However, sodium pentobarbital and diazepam caused synergistic exacerbation of the ulcer when combined with GABA. Since it is known that systemically administered GABA can not penetrate into the brain, these results suggest that systemically administered GABA may stimulate the cholinergic transmission mediating the activation of peripheral GABA receptors, resulting in the exacerbation of indomethacin-induced ulceration.

Animals↗
PubMed1988

Isolated dog hearts prepared in cold tyrode solution and reperfused with arterial blood are functionally and ultrastructurally normal.

Isolated dog whole heart preparations run by means of cross-circulation with support dogs were prepared in two different ways. In one way the donors' hearts were quickly removed, and cannulation of their major vessels, insertion of a latex balloon into the left ventricle, etc. were all done in cold Tyrode solution in the condition of heart-anoxia within 30 min and then reperfused with arterial blood of support dogs (Group A). In the other, cannulation of the major vessels of the donors' hearts were done in the state of "beating heart" (Group B). In these two kinds of preparations we compared basal cardio-coronary measurements (coronary blood flow, left ventricular pressure (LVP), its first derivative (LV dP/dt) and myocardial oxygen consumption (MVO2) and ultrastructure of the myocardium at various periods of the experiments. There were no significant differences in these cardio-coronary measurements and ultrastructural findings. Furthermore, Group A preparations kept stable levels of cardio-coronary measurements for 5 hr or more and responded normally to isoproterenol. Therefore, isolated, blood-perfused dog whole hearts prepared in cold Tyrode solution and reperfused by means of the cross-circulation method would be useful for physiological, pharmacological and biochemical studies.

Animals↗
PubMed1988

Cardiovascular profile of AN-132, a new diamine derivative antiarrhythmic agent, revealed in the isolated, blood-perfused dog heart.

The cardiac and coronary effects of AN-132, a new antiarrhythmic agent, were investigated in isolated, blood-perfused atrioventricular (AV) node, sinoatrial (SA) node and papillary muscle preparations of dogs. AN-132 was administered intraarterially. In AV node preparations, whether injected into the anterior septal artery (ASA; supplying the His-Purkinje-ventricular system) or the posterior septal artery (PSA; supplying the AV node), AN-132 prolonged AV conduction time and produced second- or third-degree AV block at large doses in some preparations. Moreover, only when injected into the ASA AN-132 produced a broadening and diminution of amplitude of bipolar electrograms obtained from the right bundle branch and the ventricular septum. In SA node preparations, AN-132 decreased sinus rate and produced atrial standstill at large doses in some preparations. In paced papillary muscle preparations, AN-132 reduced the force of contraction. In spontaneously beating papillary muscle preparations, AN-132 decreased the rate of automaticity and the force of contraction. In all preparations, AN-132 produced a transient increase in blood flow only at large doses. The order of potencies of AN-132 based on the doses that produced 15% suppressions of the above cardiovascular variables was as follows: cardiac muscle contraction greater than ventricular automaticity greater than or equal to intraventricular conduction greater than AV nodal conduction greater than or equal to coronary blood flow greater than SA nodal automaticity.

Anilides↗
PubMed1988

Evaluation of mass screening for thyroid cancer.

Mass screening for detecting both thyroid and breast cancer in adult women was carried out in Gunma Prefecture, Japan, between 1980 and 1986. The total number of subjects during the seven years was 152,651. The first screening was by inspection and palpation using experienced surgeons. Thyroid abnormalities were found in 5,902 subjects (3.9%) and 3,804 (2.5%) were required to attend a second examination. Thyroid carcinoma was detected in a total of 216 subjects, a detection rate of 0.14%. The detection rate for thyroid cancer was twice as high at the initial screening (0.19%) than that at subsequent periodic screenings (0.09%). Histological classifications of the detected thyroid cancers were: papillary carcinoma, 189 cases (87.5%); follicular carcinoma, 26 (12%); medullary carcinoma, 1 (0.5%). Eighty-seven percent of the thyroid cancers were asymptomatic at the time of screening. The tumor size were 2 cm or less in 126 patients (58.3%). Thyroid cancer detected by mass screening was revealed at an earlier stage and showed a significantly better survival rate compared to that of our usual outpatients. As differentiated carcinoma has been found at a higher incidence by mass screening, the program is useful for the early detection and treatment of thyroid cancer.

Adult↗
PubMed1988

[Cerebral ischemia (1)--Reversibility of ischemic lesion and CT findings].

Two hundred and twenty-one patients with cerebral cerebral ischemic attack in the middle cerebral artery territory were investigated. Those patients manifested several clinical types, TIA: 31, stroke with full recovery: 50, minor completed stroke: 54 and major completed stroke: 86 cases. CT classification was made 3 weeks after the ischemic attack based on the characteristic arterial topography. We discussed in this paper what kind of ischemic lesion had greater possibility of recovery from ischemic lesion had greater possibility of recovery from ischemia focusing on the retrospective study of clinical symptoms, CT classification and angiographic findings. We also referred to the other factors influencing the reversibility of an ischemia such as lacunae and PVH (periventricular hypodensity). The extent of and LDA on CT scan closely correlated with clinical symptoms, CT classification and angiographic findings. We also referred to the other factors influencing the reversibility of an ischemia such as lacunae and PVH (periventricular hypodensity). The extent of an LDA on CT scan closely correlated with clinical types (Table 2). The reversibility of type I was excellent, however aged patients over 70 with PVH and ventricular dilatation developed permanent neurological impairment associated with dementia. The reversibility of a small infarction in the basal ganglia (type II) depended mainly on the involvement of the internal capsule. Infarction involving a cortex (type IV and type V) invariably resulted in permanent neurological deficits except for the rare cases with involvement of silent areas. CT classification of type III, so called demarcation zone infarction, developed various clinical types, and showed transient functional disturbance of the cortex without an infarction i the cortico-subcortical region.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Clinical studies on S 6472 granule preparation (sustained-release cefaclor) in chronic respiratory tract infections].

S 6472 granule preparation (sustained-release cefaclor) was orally administered to 15 patients with chronic respiratory tract infections (2 acutely exacerbated cases of chronic bronchitis, 13 cases of secondary infections consisting of 1 case of bronchial asthma, 2 cases of bronchial asthma/pulmonary emphysema, and 10 cases of bronchiectasis) at a daily dose of 750 mg divided into 2 doses administered after breakfast and dinner, for a duration of 14 days. The drug was ineffective in 3 of the 10 cases of bronchiectasis but was effective in the other 12 cases, with a rate of efficacy of 80%. There were no side effects of abnormal laboratory findings due to administration of this drug.

Administration, Oral↗
PubMed1988

Emphysema associated with complete absence of alpha 1- antitrypsin in serum and the homozygous inheritance [corrected] of a stop codon in an alpha 1-antitrypsin-coding exon.

Homozygous inheritance of the null bellingham alpha 1-antitrypsin (alpha 1AT) gene is associated with early-onset emphysema, resulting from the lack of alpha 1AT to protect the lung from neutrophil elastase. Cloning and sequencing of the null bellingham gene demonstrated that the promoter region, coding exons, and all exon-intron junctions were normal except for a single base substitution in exon III, causing the normal lys217 (AAG) to become a stop codon (TAG). Evaluation of genomic DNA of family members by using oligonucleotides directed toward this region demonstrated that the index case had inherited this mutation in a homozygous fashion. Although the consequences to the individual (i.e., emphysema) are identical to those associated with the common homozygous Z mutation, the homozygous null bellingham form of alpha 1AT deficiency has a very different genetic basis.

Adult↗