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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 1,081 records · Page 60Linked to original sources

[Correlation study of cancer mortality and food consumption].

The geographical relationships between cancer mortality and food consumption were analyzed by means of extensive uses of correlation coefficiencies, factor analysis, multiple regression analysis, cluster analysis and path analysis. The results for the countries in the world varied broadly due to selection of the countries analyzed. The results for prefectures in Japan showed differences between males and females especially with regard to stomach cancer. The present study shows the importance of careful selection of geographical and other variables when making correlation studies.

Alcohol Drinking↗

[Study on extensive lymph node dissection: metastatic lymph nodes in papillary carcinoma of the thyroid].

Bilateral cervical lymph node dissection was performed in 71 cases of papillary thyroid carcinoma, considered to be relatively early cases because of mobility, irrespective of the size of tumor or presence of node enlargement. Of these, 33 cases received additional node dissection of the anterosuperior mediastinum through longitudinal sternotomy. The number of lymph nodes examined per subject averaged 89.9, the number of metastatic nodes was 13.8, and metastasis was noted in 88.7% of all cases. Lymph node metastasis tended to be more frequent on the affected side, but was simultaneously scattered over the whole cervical area. As to sites, metastasis of paratracheal nodes on the affected side occurred at a frequency of 66.2%, inferior and superior jugular nodes at 62.0% and 59.0% respectively, pretracheal nodes at 50.7%, and tracheoesophageal nodes at 47.9%. The high incidence of para- and pretracheal nodes suggests that the lymph flow in this direction is of great importance in metastasis. In fact, lymph nodes in the mediastinum, which were directly continuous with these nodes, showed as high as 39.4% metastasis in cases of anterosuperior mediastinal extirpation. This extensive node dissection is considered to be very preferable as at least the agony of survival with carcinoma can be lessened.

Adult↗

[A clinical study on primary renal pelvic tumors].

Sixteen cases of primary renal pelvic tumor treated at our Department between July, 1971 and June, 1984, were reviewed. The sixth decade predominated over other age groups and occupied 47.3% of all cases (average: 63.9 years). The sex ratio was 4.3:1 with male patients predominating over female patients. The incidence of the affected side was equal; 8 cases in the right and 8 cases in the left renal pelvis. The most common initial symptom was macroscopic hematuria in 13 cases (81.2%), followed by flank pain in 2 cases (12.5%). The major findings in IVP were filling defect in 11 cases (68.7%) and non-visualizing kidney in 4 cases (25.0%). Positive urinary cytology was obtained in 6 cases (49.1%) by voided urine specimen and 4 cases (50.0%) by catheterized urine specimen. Histologically, all cases were transitional cell carcinoma; 11 of them were low stage and 5 were high stage at the initial diagnosis. Nine patients(56.1%) were treated by total nephroureterectomy associated with partial cystectomy. The over all survival rate at 1,2,3,4 and 5 years was 86%, 78%, 78%, 68% and 68%, respectively, by the Kaplan-Meier method. The five year survival rate was 80% for the low stage group and 0% for the high stage group. (p less than 0.05, generalized Wilcoxon test). The five year survival rate was 83% for the low grade group and 40% for the high grade group. (p less than 0.05, Generalized Wilcoxon test) Among several factors, stage and grade of the tumor were the most influencing factors for prognosis.

Aged↗

Noradrenergic inhibition of the release of substance P from the primary afferents in the rabbit spinal dorsal horn.

To investigate pre-synaptic influence of the descending noradrenergic system on the primary afferents containing substance P (SP), effects of noradrenergic manipulations on the in situ release of immunoreactive SP (iSP) from the dorsal horn were examined in the thalamic rabbit. Local application of noradrenaline (10 microM) to the dorsal horn produced complete inhibition of the noxious mechanical stimuli-evoked release of iSP. This effect was reversed by yohimbine (the more selective alpha 2-blocker, 10 microM) and partially antagonized by prazosin (the more selective alpha 1-blocker, 10 microM). The resting release of iSP was not affected by noradrenaline. The noxious mechanical stimuli-evoked release of iSP was significantly increased by acute spinal transection and local application of yohimbine (10 microM) alone to the dorsal horn. Prazosin (10 microM) slightly increased the evoked iSP release, and a beta-blocker metoprolol did not affect it. These results suggest that the nociceptive primary afferents containing SP are tonically inhibited by the descending noradrenergic system linked to alpha-adrenoceptors, and that such alpha-adrenoceptors located on the primary afferent terminals may be one of the sites of action of noradrenaline spinal analgesia. In contrast to the evoked iSP release, the resting iSP release was increased only by acute spinal transection and not by yohimbine, prazosin and metoprolol. All these observations suggest that tonic inhibition in propriospinal neurons containing SP is mediated by a non-noradrenergic system.

Adrenergic Fibers↗

Inhibitory action of phorbol myristate acetate on histamine secretion and polyphosphoinositide turnover induced by compound 48/80 in mast cells.

Rat peritoneal mast cells which had been preincubated with phorbol myristate acetate (PMA, 10 - 100 ng/ml) for 5 min did not elicit the full histamine secretion induced by a potent secretagogue, compound 48/80. Furthermore, this PMA-treatment was found to inhibit the agonist-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) in [32P]labeled cells. However, it was also observed that the level of [32P]PIP2 was markedly reduced by 5 min-incubation with PMA. This suggests the enhanced hydrolysis of PIP2 by PMA which was reflected in a greater formation of inositol trisphosphate (IP3). These observations indicate that the formation of IP3 may not be profoundly related to secretory response in mast cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive neurons and axon terminals of the nucleus of the tractus solitarius of the rat.

This study was an examination of the ultrastructural characteristic features of calcitonin gene-related peptide (CGRP)-like immunoreactive neurons and their axon terminals in the nucleus of the tractus solitarius of the rat. Some axon terminals were identified as receiving synaptic inputs from non-immunoreactive axon terminals. This may suggest that part, if not all, CGRP containing afferents are affected presynaptically by other afferents.

Animals↗

A wasp venom mastoparan-induced polyphosphoinositide breakdown in rat peritoneal mast cells.

The phospholipid metabolism of rat peritoneal mast cells stimulated with mastoparan, a secretagogue purified from wasp venom, was investigated. Mastoparan at 20 micrograms/ml caused a rapid secretion of histamine. Mastoparan induced a transient decrease of phosphatidylinositol 4,5-biphosphate on 32P labeling and generation of a water-soluble degradation product, inositol trisphosphate on [3H]inositol labeling, suggesting the activation of phospholipase C upon stimulation.

Animals↗

Degradation of kyotorphin by a purified membrane-bound-aminopeptidase from monkey brain: potentiation of kyotorphin-induced analgesia by a highly effective inhibitor, bestatin.

Kyotorphin (Tyr-Arg) was rapidly degraded in rat brain homogenates and the Vmax and Km were 29.4 nmol/mg protein/min and 16.6 microM, respectively. This degradation was effectively inhibited by bestatin (IC 50; 0.08 microM) and p-chloromercuribenzoate (IC 50; 0.70 microM). Kyotorphin was also degraded by a membrane-bound aminopeptidase from monkey brains. The Vmax and Km of kyotorphin degradation by the aminopeptidase were 20.0 nmol/mg protein/min and 29.2 microM, respectively. The degradation of kyotorphin was also inhibited effectively by bestatin (KI; 0.4 microM). Co-administration with bestatin 50 micrograms (i.cist.) potentiated the analgesic effects of kyotorphin (i.cist.) by 4.8 times, and these effects were abolished by pretreatment with naloxone 0.5 mg/kg s.c. These results suggest that potentiation of analgesia by bestatin may be due to the protection against the degradation of kyotorphin and released enkephalin by a membrane-bound aminopeptidase.

Aminopeptidases↗

Synaptic interaction between catecholaminergic neurons and substance P-immunoreactive axons in the caudal part of the nucleus of the solitary tract of the rat: demonstration by the electron microscopic mirror technique.

The 'mirror technique' was applied in immunoelectron microscopy to demonstrate the synaptic relationship between neuronal structures containing catecholamines and substance P in the caudal part of nucleus of the solitary tract in the rat, using antisera against tyrosine hydroxylase and substance P. Substance P-immunoreactive axon terminals were shown to make two types of synaptic contacts (asymmetrical and symmetrical) with catecholaminergic neurons. It is concluded that substance P afferents can directly affect catecholaminergic neurons in this nucleus via synapses.

Animals↗

Arachidonic acid release in rat peritoneal mast cells stimulated with antigen, ionophore A23187, and compound 48/80.

Rat peritoneal mast cells respond to various types of secretagogues, such as antigen (receptor-mediated), A23187 (calcium mobilizing), and compound 48/80 (membrane perturbing), and release arachidonic acid from membrane phospholipids prelabeled with [3H]arachidonate. The rate of arachidonic acid liberation varied from one stimulant to the other. Ionophore A23187 (0.1 micrograms/ml) appeared to be most potent in releasing arachidonate among the three stimulants at which doses each secretagogue caused almost equivalent histamine secretion. However, upon stimulation with these three secretagogues, the radioactivity of phosphatidylcholine (PC) was markedly reduced with a concomitant increase of arachidonate radioactivity. Hydrolysis of PC by phospholipase A2 is likely to be the major route of arachidonic acid liberation in either IgE-mediated or non-IgE activation in mast cells.

Animals↗

The synaptic relationship between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and their axon terminals in the rat small intestine: light and electron microscopic study.

The present study demonstrates synaptic contacts between vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons and immunoreactive axon terminals in the submucous and myenteric plexuses of the rat small intestine. Our observations suggest that VIP afferents directly affect the VIP neurons in the small intestine via synapses.

Animals↗

Antinociceptive effects of intrathecal opioids, noradrenaline and serotonin in rats: mechanical and thermal algesic tests.

Antinociceptive effects of intrathecal injections of morphine, methionine-enkephalin, noradrenaline and serotonin were examined in rats, using 3 different methods: the tail-pinch, hot-plate and tail-flick tests. The order of sensitivity of the 3 methods to noradrenaline in the production of antinociception was tail-pinch greater than tail-flick greater than hot-plate, while that of morphine, methionine-enkephalin and serotonin was tail-flick greater than hot-plate greater than tail-pinch. These results indicate that intrathecal noradrenaline, but not methionine-enkephalin and serotonin, produces more potent inhibition of the mechanical nociception than does the thermal one, and suggest a closer relationship of the descending noradrenergic system to the mechanical nociceptive system, in the spinal cord of rats.

Analgesics↗