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Biomedical subjects

T Endo

Publications and source records attributed to T Endo.

1,268 records · Page 71Linked to original sources
PubMedDate not supplied

5-Hydroxytryptamine (5-HT)-induced depolarization in isolated abdominal vagus nerves in the rat: involvement of 5-HT3 and 5-HT4 receptors.

In this study, we developed an electrophysiological technique for the in vitro measurement of isolated abdominal vagus nerve depolarization in the rat. This technique was used to compare abdominal and cervical vagus nerve depolarization values. Both 5-HT and a selective 5-HT3 agonist, 2-CH3-5HT, caused a concentration-dependent depolarization in rat isolated abdominal vagus nerves in vitro. Isolated cervical vagus nerves also showed concentration-dependent depolarization, although the isolated cervical vagus nerve depolarization was approximately 60% of that of the isolated abdominal vagus nerves at similar concentration ranges of 5-HT and 2-CH3-5HT in vitro. In isolated abdominal vagus nerves, a selective 5-HT3 antagonist, granisetron, produced a concentration-dependent decrease, but reduced the maximal response of 5-HT-induced depolarization in vitro. In isolated abdominal vagus nerves, selective 5-HT4 antagonist, SB204070, produced parallel and concentration-dependent shifts to the right on the concentration-response curves to 5-HT in vitro. These findings suggest that this electrophysiological method for evaluating isolated abdominal vagus nerve depolarization is a useful technique for the estimation of 5-HT-induced depolarization.

Abdomen↗
PubMedDate not supplied

The effects of nabumetone, a cyclooxygenase-2 inhibitor, on cisplatin-induced 5-hydroxytryptamine release from the isolated rat ileum.

In order to elucidate 5-HT release influenced by PGE2 in the background of the anticancer drug-induced emesis, the effect of nabumetone, a COX-2 inhibitor, on the release of 5-HT from the isolated rat ileum was investigated. PGE2 produced a concentration-dependent increase (10(-9) to 10 M) and decrease (10(-8) to 10(-6) M) in 5-HT release. Arachidonic acid also demonstrated a similar bell-shaped 5-HT release. The arachidonic acid-induced 5-HT release at 3 x 10(-6) M (313.04 +/- 25.90%) was significantly inhibited by the concomitant perfusion with BRL10720 (10(-6) M) (161.98 +/- 19.4%, p<0.01), an active metabolite of nabumetone, or indomethacin (3 x 10(-7) M)(190.01 +/- 16.19%, p<0.05). BRL10720 (10(-6) M)(428.57 +/- 51.72%, p<0.05) significantly inhibited the increase in 5-HT release induced by cisplatin (10(-6) M)(748.56 +/- 136.31%), suggesting that PGE2would be involved in cisplatin-induced 5-HT release. The increase in 5-HT release from the isolated ileum 72 hrs after cisplatin administration, in a delayed-emesis animal model, was significantly inhibited by the in vivo 3-day administration of nabumetone or BRL10720, but was not affected by the 3-day administration of dexamethasone. After 72 hours, however, the in vivo 3-days administration of nabumetone, BRL10720 or dexamethasone had no effect on the increase in ileal 5-HT levels induced by cisplatin. The use of COX-2 inhibitors to ameliorate delayed emesis induced by cisplatin-based anticancer chemotherapy has been proposed. On the other hand, there is a possibility that dexamethasone works through a mechanism other than 5-HT release in delayed emesis.

Animals↗
PubMedDate not supplied

Clinical evaluation of assistant diagnostic system for mammograms using the auto-analyzing method.

Clinical usefulness of a newly developed auto-analyzing system of mammograms to search the abnormal dense areas such as cancer lesions was studied. 345 breasts including 86 cancers, 52 mastopathies, 18 fibroadenomas, 13 cysts, 4 lipomas and 172 normals were analyzed and compared with final diagnosis. 84 of 86 cancer lesions were correctly pointed out (sensitivity: 97.9%). Based on the gradient of the density, the ranking of the cancer or calcified lesions among suspected regions in a mammogram was decided. 55 lesions of them (64.0%) were ordered at the first rank and 83 (96.5%) were in the upper three ranks. 68 of 74 breasts with calcifications were correctly diagnosed and 48 of them were ranked in the upper three ranks. Although further improvement of the system is needed, this system will be a useful assistance for screening the breast cancer in the analyses of mammograms.

Breast Neoplasms↗
PubMedDate not supplied

Combination of epidural morphine and fentanyl for postoperative analgesia.

The rapid onset of epidural fentanyl could be used to cover the latency period of epidural morphine, thus potentiating analgesia during anesthesia regression after short-acting local anesthetics and possibly extending morphine analgesia for longer duration. The object of this study is to determine whether there are clinical advantages or disadvantages of combining epidural morphine and epidural fentanyl for postoperative analgesia. Patients scheduled for gynecologic procedures were assigned to two groups (n = 54 for each): Group 1 receiving 4 mg epidural morphine, and Group 2 receiving 4 mg epidural morphine and 100 micrograms fentanyl 30 minutes before the estimated completion of the surgery using lidocaine epidural anesthesia. Comparisons were made with regard to: (1) times before the first supplemental analgesic for incisional pain, (2) numbers of supplemental analgesic during the first 48 hours postoperatively, and (3) adverse effects. The two groups were comparable. The number of patients requiring supplemental analgesics between the fourth and 17th hours was significantly greater in Group 1 (n = 10, compared to n = 0 for Group 2; p less than 0.05). The mean time before the first supplemental analgesic was significantly longer in Group 2 (p less than 0.05). The number of supplemental analgesics during the first 48 hours was significantly less in Group 2 (p less than 0.01). No significant difference was found regarding adverse side effects. The results obtained confirm the potential desirability of combining epidural morphine and epidural fentanyl for postoperative analgesia.

Adult↗
PubMedDate not supplied

Cerebral black blood MR angiography with the interleaved multi-slab three-dimensional fast spin echo sequence.

To overcome the disadvantages of conventional three-dimensional time-of-flight MR angiography (3D-TOF), such as saturation or intravoxel dephasing, black blood MR angiography (BB-MRA) using an interleaved multi-slab 3D fast spin echo sequence was developed and evaluated clinically. In major branches, the contrast-to-noise ratio of the flow was not as good as 3D-TOF in BB-MRA. However, in-plane slow flow and large aneurysm were visualized better on BB-MRA than on 3D-TOF. Furthermore, BB-MRA could provide wider coverage than 3D-TOF. BB-MRA using interleaved multi-slab 3D fast spin echo is now feasible and complementary to 3D-TOF.

Cerebrovascular Circulation↗
PubMedDate not supplied

Screening helical CT for mass screening of lung cancer: application of low-dose and single-breath-hold scanning.

PURPOSE: To investigate the usefulness of helical CT with low-dose and single-breath-hold scanning for lung cancer screening. MATERIALS AND METHODS: Twenty-four helical CT scans of the lung were performed using various parameters in 10 healthy volunteers. The effects of tube current and pitch were evaluated by assessment of image quality and detection of simulated nodules. Screening helical CT was performed at 120 kVp, 50 mA, 1 sec/rotation, 10 mm collimation, and a pitch of 2.0 in 110 patients. The ability of this method to detect nodules and masses, focal parenchymal opacities, and diffuse fibrotic changes was evaluated using conventional CT as the gold standard. RESULTS: A reduction in tube current to 50 mA did not significantly change the assessment of image quality or detection of simulated nodules. Although these factors were degraded by increasing the pitch, there was no significant difference between 1.5 and 2.0. Screening helical CT permitted the entire lung to be scanned with ease during a single-breath-hold in all patients. This method detected 177 of 196 nodules and masses (87 of 91 lesions greater than 5 mm in diameter), 54 of 57 focal parenchymal opacities, and 15 of 15 cases with fibrotic changes. CONCLUSION: Screening helical CT with low-dose and single-breath-hold scanning shows promise for lung cancer screening.

Adult↗