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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 1,603 records · Page 89Linked to original sources
PubMed1976

Electrophoretic pattern of amylase isoenzymes in serum and urine of normal persons.

We separated and measured amylase isoenzymes in the serum and urine of 3036 normal persons by electrophoresis on a thin layer of polyacrylamide gel. We wished to establish the normal pattern of these isoenzymes and to evaluate the usefulness of this method of electrophoresis in clinical diagnosis. Results for patients with hyper- or hypofunctioning pancreas and salivary glands suggested that essentially all the isoamylases in human serum and urine are derived from the salivary glands and the pancreas, and revealed that isoamylases of more than 98% of normal persons consisted of two major isoenzymes and two to three minor ones. Although these observations indicate that data on changes in the proportion of amylase activity of each isoenzyme can be useful in clinical medicine, the following points should be remembered: (a) quantitative differences in the isoenzyme pattern were observed, depending upon the condition of the samples; (b) because the proportion of isoamylase activity in serum of different normal persons differs, seriatim determination of amylase isoenzymes is necessary; and (c) because five different genetically controlled types of isoamylases were observed in normal persons, genetic investigations are also necessary.

Adult↗
PubMed1976

[Mechanism of the contracting actions of K, acetylcholine and Ba on the isolated rat rectum, with special reference to its relationship to Ca].

The contractile mechanism of K, ACh and Ba were investigated in relation to the mobilization of Ca in the rat's isolated rectum. Contractions by K, ACh and Ba consisted of the phasic contraction and the subsequent tonic contraction. From the effects of metabolic inhibition (anoxia, DNP) and Ca removal from bath solution on the contractions by these three agents, the following assumptions have been made: the phasic contractions by K and ACh are iduced by the release of Ca from the store sites and the passive influx of Ca, whereas that by Ba is induced by the release of Ca. Tht tonic contractions by K and ACh are maintained mainly by the active influx of Ca, whereas that by Ba is maintained by the active influx of Ca and the release of Ca. In addition, the direct stimulation to the contractile elements of muscle is partly concerned with the Ba-induced contraction. In the muscle cell membrane, three divisions of Ca store; the first is the store where Ca is most easily released, the second is the store where Ca is comparatively easily released and the third is the store where Ca is not easily released. K releases Ca from the first store, ACh does so from the first and second stores, and Ba does so from these three stores for producing contraction. These assumption were further supported by the analysis of the concentration action curves of the influence of Ca removal from bath solution on the phasic contractions and the tonic contractions induced by the three agents.

Acetylcholine↗
PubMed1976

[Antispasmodic mechanisms of actions of isoproterenol and papaverine with special reference to their relation to Ca (experiments using the isolated rat rectum)].

Antispasmodic mechanisms of isoproterenol and papaverine were investigated in relation to the mobilization of Ca in the rat's isolated rectal muscle. The findings on the relaxing effects of isoproterenol and papaverine on the contractions induced by increasing concentrations of K and on the modifications in the shape of K- and ACh-induced contractions by these two agents suggest that the antispasmodic mechanism of isoproterenol may be related to inhibition of the transmembrane influx of Ca as well as release of Ca, whereas that of papaverine may be related to not only inhibition of the transmembrane influx of Ca and release of Ca but also to inhibition of the ability of contractile elements responding to Ca. Furthermore, analysis of the concentration-action curves of K and acetylcholine concerning the phasic and the tonic contractions affected by isoproterenol and papaverine (Table 1) provide additional evidence for such a hypothesis.

Acetylcholine↗
PubMed1976

[Influence of removal of Na from the bath solution on the antispasmodic actions of isoproterenol and papaverine, with special reference to their relations to Ca (experiments using the isolated rat rectum)].

Influence of the Na removal from bath solution on the antispasmodic actions of isoproterenol and papaverine against the phasic contractions by K and acetylcholine were investigated in relation to the mobilization of Ca in isolated rectal strip from the rat. Effect of the Na removal on the uptake of intracellular Ca into storage sites was also examined. The Na removal attenuated the inhibitory actions of isoproterenol and papaverine on the release of Ca, whereas the Na removal did not affect the inhibitory action of isoproterenol on Ca influx and that of papaverine on the response of the muscle contractile elements. Furthermore, the Na removal inhibited the uptake of intracellular Ca into storage sites. Thus, it is suggested that isoproterenol and papaverine may generate the inhibitory action on the release of Ca by accelerating Ca uptake into storage sites, therefore the antispasmodic actions of these agents are depressed by the deprivation of Na from the bath solution which attenuates the Ca uptake.

Acetylcholine↗
PubMed1975

Labyrinthine influence on cat forelimb motoneurons.

1. Intracellular responses in forelimb motoneurons to electrical stimulation of the whole labyrinth and of individual semicircular canal nerves were studied in decerebrated, unanesthetized cats. 2. Stimulation of the whole labyrinth typically produced EPSPs, usually bilaterally, in forelimb extensor (LON, LAT, MED) and shoulder (SI) motoneurons and bilateral IPSPs in forelimb flexor (BIC) motoneurons. 3. Latencies of PSPs indicated that most of those in extensor motoneurons were trisynaptic and many seen in flexor motoneurons may involve four synapses. 4. In the cells sampled, stimulation of the anterior, horizontal or posterior canal nerves often evoked EPSPs in extensor and IPSPs in flexor motoneurons, both ipsi- and contralaterally. Responses to canal stimulation were weaker and more variable than those to stimulation of the whole nerve. 5. Transection of the MLF in the lower medulla had no effect on PSPs evoked in forelimb motoneurons. Lesions in the medulla in the area of the LVST greatly reduced the occurrence of contralateral EPSPs in extensor and IPSPs in flexor motoneurons. The pathway linking labyrinths to forelimb motoneurons therefore appears to include the LVST. Hemisection shows that the pathway to contralateral motoneurons descends in the cord on the side of the stimulated labyrinth before crossing to influence these cells. 6. Labyrinthine control of forelimb motoneurons is less direct than control of neck and back motoneurons. It is suggested that the interneuron in the pathway to forelimb motoneurons is the site of integration of labyrinthine with other reflexes.

Animals↗
PubMed1975

Role of preoperative administration of bleomycin and radiation in the treatment of esophageal cancer.

The preoperative use of Bleomycin (BLM) alone or combined with irradiation in the treatment of esophageal cancer was evaluated in 58 patients who underwent surgical removal of the lesion for the past three and a half years. Histologic study showed such preoperative treatment is effective in inducing favorable changes in neoplastic cells in 69 per cent (40/58) of the primary lesions and in a significant number of involved lymph nodes of the second or the third groups. The study clearly suggests that preoperative Bleomycin administration combined with irradiation may be an useful adjunct preoperative procedure in esophageal cancer.

Adult↗