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Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 505 records · Page 28Linked to original sources
PubMed1991

Serial angiography in a spontaneous dissecting anterior cerebral artery aneurysm.

Intracranial dissecting aneurysms are uncommon, and little is known concerning the natural history of these lesions. In this paper we present a rare case of dissecting aneurysm of the anterior cerebral artery in which a true diagnostic sign of "double lumen" was demonstrated. Sequential changes in angiographic features shown on serial angiographic studies are described, and diagnosis is briefly discussed.

Aortic Dissection↗
PubMed1991

Pinch grafting of the open mastoid cavity.

Secondary pinch skin grafting was performed on the mastoid cavities to promote healing of the mastoid wound after ear surgery using the open technique. Pinch grafts (multiple small grafts of the epidermal layer) were transplanted in 20 patients, soon after the mastoid cavities were covered with healthy granulation tissue in a mean of 28.5 days after the initial surgery. The grafts adapted well in 18 of the 20 patients. Epidermization was complete in a mean of 11.1 days after grafting, that is, within 40 days after the initial ear surgery. On the other hand, epidermization in 10 cases without grafting was completed in a mean of 83.3 days after the ear surgery. Thus, the pinch grafts reduced healing time by more than 40 days. The secondary application of pinch grafting was beneficial for healing of exposed mastoid cavities caused by use of the open technique tympanoplasty or radical mastoidectomy.

Cholesteatoma↗
PubMed1991

Suppression of virulence factors of Pseudomonas aeruginosa by erythromycin.

The effects of erythromycin stearate over a concentration range of 0.1-10 mg/l on production of elastase, protease and leucocidin by clinical isolates of Pseudomonas aeruginosa were investigated. Growth of P. aeruginosa N42 in broth was not affected significantly during 24 h culture with erythromycin (0.1-10 mg/l), although extracellular protein contents were reduced by erythromycin at concentrations of 0.1-1.0 mg/l. Production of elastase and protease by strain N42 was significantly suppressed by erythromycin with a maximum inhibition at 0.5 mg/l, but the complete inhibition of enzyme production was not achieved. In contrast, leucocidin production by strain N42 was completely impaired by erythromycin at concentrations of 0.1-5.0 mg/l. Although the leucotoxic activity, as determined by vital staining, was not detected, the leucocidin fraction prepared from the autolysate of strain N42 cultured with 10 mg/l of erythromycin induced morphological changes in human leucocytes, resulting in release of elastase. Erythromycin exerted similar effects on other clinical isolates of P. aeruginosa. These findings indicate that erythromycin might have a role in P. aeruginosa infection, although it has no direct antibacterial activity.

Bacterial Proteins↗
PubMed1991

Host responses and neuroendocrinological changes in pyrexia in childhood.

Host responses and neuroendocrinological changes during pyrexia in childhood were studied. Serum IL-1 beta could not be detected in most subjects either during pyrexia or in afebrile periods. IL-1 beta was detected in two cases, increasing during pyrexia and decreasing during the afebrile period. Plasma ACTH increased during pyrexia, but this was not statistically significant. Serum cortisol during pyrexia increased to around twice the normal value, and many subjects showed a high level of arginine vasopressin. The subjects, who did not develop dehydration, showed a decrease in serum osmolality and serum sodium during the pyrexia period. Serum Fe and Zn decreased, but serum Cu increased during both periods. It could not be confirmed that IL-1 activates the hypothalamic-pituitary-adrenal axis during pyrexia. It is concluded that AVP is important in the control of fever and the maintenance of homeostasis of body fluid during pyrexia.

Acute Disease↗
PubMed1991

L-arginine induces relaxation of rat aorta possibly through non-endothelial nitric oxide formation.

1. The relaxation of rings of rat thoracic aorta induced by L-arginine and its derivatives was investigated. 2. L-Arginine (0.3-100 microM), but not D-arginine, induced relaxation of the arteries, which was detectable after 2 h and maximal after 4-6 h on its repeated application; it was endothelium-independent. 3. L-Arginine methyl ester, N alpha-benzoyl L-arginine and L-homo-arginine had essentially similar effects to those of L-arginine. 4. NG-nitro L-arginine methyl ester (L-NAME, 3 microM), NG-nitro L-arginine (L-NNA, 1 microM) and NG-monomethyl L-arginine (L-NMMA, 10 microM), inhibitors of nitric oxide (NO) formation from L-arginine, inhibited or reversed the L-arginine-induced relaxation, irrespective of the presence or absence of the endothelium. In contrast, NG-nitro D-arginine was without effect. 5. Haemoglobin (Hb, 10 nM) and methylene blue (MB, 0.3 microM) inhibited or reversed the L-arginine-induced relaxation. 6. L-Arginine (1-100 microM), but not D-arginine, increased guanosine 3':5'-cyclic monophosphate (cyclic GMP) levels in the tissues that relaxed in response to L-arginine. This effect of L-arginine was suppressed by Hb (3 microM), MB (1 microM) and L-NAME (100 microM). Removal of the endothelium did not significantly alter the L-arginine-induced cyclic GMP production. 7. These results suggest that L-arginine itself caused a slowly developing relaxation of rat aorta, possibly via formation of NO by an endothelium-independent mechanism.

Animals↗
PubMed1991

Ambroxol inhibits Na+ absorption by canine airway epithelial cells in culture.

To study the effect of ambroxol on ion transport functions of airway mucosa, we measured bioelectric properties of canine cultured tracheal epithelium under short-circuit conditions in-vitro. Addition of ambroxol to the submucosal but not to the mucosal solution in an Ussing chamber decreased short-circuit current, transepithelial potential difference and cell conductance. The ambroxol-induced decrease in short-circuit current was not affected by bumetanide or diphenylamine-2-carboxylate, but it was abolished by pretreatment of cells with amiloride. These results suggest that ambroxol may selectively inhibit Na+ absorption by airway epithelium, thereby increasing water composition in airway surface fluid and reducing mucus viscosity.

Absorption↗
PubMed1991

[The study on bacterial infection in chronic lower respiratory tract infection--from the viewpoints of acute and chronic infection].

Using mainly changes in the amount of sputum as an index of the infectious course of chronic lower respiratory tract infection associated with purulent sputum over years, the disease was divided into stable and acute exacerbated phases and a bacteriological investigation using transtracheal aspiration (TTA) conducted. TTA was performed 107 and 45 episodes during stable phases and acute exacerbated phases respectively. Monomicrobial and polymicrobial infection were detected most frequently during the stable and acute exacerbated phases respectively (p less than 0.01). During the stable phases, the single organisms detected most frequently were H. influenzae (26 episodes) and P. aeruginosa (20 episodes), while in the cases in which multiple organisms were detected during stable phases, combination including H. influenzae were most common (19 episodes). H. influenzae was the most frequently detected organism in cases showing single organisms during acute exacerbated phases (7 episodes). In the cases in which multiple organisms were detected as well, H. influenzae was the most commonly detected organism assumed to predispose to exacerbation (7 episodes), while P. aeruginosa was not found. These results suggest that in chronic lower respiratory tract infection. H. influenzae and P. aeruginosa are important as persistent infective organisms, while H. influenzae are important in acute exacerbation.

Acute Disease↗
PubMed1991

Atrial natriuretic factor inhibits ciliary motility in cultured rabbit tracheal epithelium.

To study the effect of atrial natriuretic factor (ANF) on airway ciliary motility, we measured ciliary beat frequency by a photoelectric method in response to ANF in cultured tracheal epithelial cells from rabbits. Addition of ANF but not [Tyr8]ANF-(5-27) decreased ciliary beat frequency in a dose-dependent fashion; the maximal decrease from the baseline value was 24.1 +/- 1.5% (+/- SE, P less than 0.001), and a half-maximal inhibitory concentration (IC50) was 3 x 10(-12) M. Inhibition of neutral endopeptidase activity by phosphoramidon (10(-6) M) or thiorphan (10(-6) M) potentiated the effect of ANF so that the dose-response curve for ANF was shifted to lower concentrations by approximately 0.5 log units (P less than 0.05, in each case). The inhibition of ciliary motility induced by ANF was not affected by the blockade of arachidonic acid metabolism with indomethacin, piroxicam, or nordihydroguaiaretic acid, but it was blocked by methylene blue, a soluble guanylate cyclase inhibitor, and was potentiated by M & B 22948, a guanosine 3',5'-cyclic monophosphate (cGMP) phosphodiesterase inhibitor. The intracellular cGMP levels were increased by ANF, an effect that was further potentiated by phosphoramidon or thiorphan. These results suggest that ANF inhibits ciliary motility presumably through a guanylate cyclase-dependent regulatory pathway and that neutral endopeptidase may play a role in modulating the ANF effect on airway mucociliary transport function.

Animals↗
PubMed1991

Pressure relationship between perilymph and endolymph associated with endolymphatic infusion.

The pressure difference between the perilymph and the endolymph following infusion of artificial endolymph into the endolymphatic space was studied in guinea pigs. Both the perilymphatic and the endolymphatic pressures were measured simultaneously with use of two sets of a servo-nulling system. Endolymphatic infusion caused pressure increases in both the endolymphatic and the perilymphatic spaces, but no measurable pressure difference between them. Soon after the endolymphatic infusion, both pressures returned nearly to the initial levels. We conclude that 1) the endolymphatic and the perilymphatic pressures are very closely related, and 2) if a physiologically significant pressure difference exists between endolymph and perilymph in endolymphatic hydrops, it is below the resolving power of the methods used in this study (+/- 0.1 mm Hg).

Animals↗
PubMed1991

[Effect of histamine on electrical properties of airway epithelium and its antagonism by azelastine].

To elucidate the mechanism of the action of histamine on bioelectric properties of the airway epithelium and the fact that the anti-allergic agent azelastine is possibly antagonistic to it, we studied canine cultured tracheal epithelium under short-circuit conditions in vitro. Addition of histamine to the submucosal but not mucosal bath of Ussing chamber increased short-circuit current (Isc) in a dose-dependent fashion, the maximal increase and the EC50 value being 5.7 +/- 0.9 microA/cm2 (mean +/- SE, p less than 0.001) and 3 x 10(-6) M, respectively. Pretreatment of tissues with pyrilamine abolished the histamine-induced increase in Isc (p less than 0.001), whereas cimetidine had no effect. In addition, the histamine action on Isc was effectively depressed by the Cl channel blocker diphenylamine-2-carboxylate, Cl-free medium, and indomethacin. The release of PGE2 and PGF2 alpha was significantly enhanced by the submucosal application of histamine. Pretreatment of tissues with azelastine dose-dependently attenuated the increase in Isc induced by 10(-4) M histamine. These results indicate that histamine increases the airway epithelial Isc via stimulation of prostaglandin synthesis and subsequent movement of Cl toward the lumen, and that azelastine may be useful in preventing histamine-induced water secretion in the airway.

Animals↗
PubMed1991

[Insidious hearing loss and facial palsy as the presenting symptoms of meningeal carcinomatosis resulting from adenocarcinoma of the lung].

An 80-year-old man was admitted to our hospital with a complaint of insidious hearing loss and facial palsy. Chest X-ray film showed an abnormal shadow in the right lower lobe. Adenocarcinoma of the lung was diagnosed by transbronchial brushing cytology. During admission, headache and dysphagia appeared, although no abnormality was detected in the brain CT and MRI. Lumbar puncture yielded adenocarcinoma cells in the cerebrospinal fluid. A diagnosis of leptomeningeal metastasis from the adenocarcinoma of the lung was considered and intrathecal administration of methotrexate was performed. The patient's condition deteriorated gradually and he died of respiratory failure. Autopsy revealed massive invasion of tumor cells in the leptomeninges of the brain and spinal cord. This case illustrates that facial nerve palsy with insidious hearing impairment may appear as the initial symptoms in meningeal carcinomatosis resulting from lung cancer metastasis.

Adenocarcinoma↗
PubMed1991

Effect of silicone oil on ocular tissues.

The effect of silicone oil on ocular tissues was investigated histopathologically in rabbit eyes by injecting silicone oil into the anterior chamber or the vitreous cavity after vitrectomy. The eyes were enucleated 3, 6, 9, 12 or 18 months after the injection and various tissues were observed by light and electron microscopy. Silicone oil was first observed in the retrocorneal membrane at 18 months after the injection. In the trabecular meshwork silicone oil was seen for the first time at 12 months after injection. Migrating cells engulfing silicone oil attached to the internal limiting membrane of the retina 3 months after the injection. Twelve and 18 months after the injection, silicone oil passed through the internal limiting membrane and was engulfed by Müller cells. These results indicate that attention should be paid to the effects of silicone oil on ocular tissues when it remains in the eye for a long time since, after a certain period, cells of the trabecular meshwork and retina may engulf silicone oil.

Animals↗
PubMed1991

[Clinical study of respiratory infections complicating bronchial asthma].

We conducted a clinical study on respiratory infections complicating bronchial asthma. Transtracheal aspiration (TTA) was performed 37 times in 22 patients. The most frequently isolated organism was H. influenzae. The patients in whom organisms were isolated on TTA had a high incidence of fever and evidence of inflammation. Antimicrobial therapy caused a decrease in indices of inflammation (white blood cell count and ESR), but was less effective against the asthmatic symptoms. Respiratory infection may play a complex role in the clinical picture of bronchial asthma.

Aged↗
PubMed1991

[The cytotoxic mechanism of tumor necrosis factor (TNF) in human osteosarcoma cell line TE85--(1). Implication of phospholipase A2 activity in cytotoxicity].

The cytotoxic mechanism of recombinant human tumor necrosis factor (TNF) in human osteosarcoma cells (TE85) was studied from the point of view of phospholipid metabolism. The TNF-induced cytotoxicity, determined by using the dye uptake method, was dose-dependent in the range of 100-10,000 U/ml. Phospholipid metabolism was analyzed in the cells labelled with [3H] arachidonic acid or [3H] glycerol. TNF stimulated the release of arachidonic acid and its metabolites from the cells in a dose-dependent manner. After TNF stimulation, the level of phosphatidylcholine (PC) decreased. Concomitantly, phospholipase A2 (PLA2) hydrolyzed PC producing a transiently increased level of lysophosphatidylcholine. ONO-RS-082, a potent PLA2 inhibitor, reduced the TNF-induced cytotoxicity and the release of arachidonic acid. These observations suggest that PLA2 may play a role in the cytotoxic effect of TNF on human osteosarcoma cells.

Cell Survival↗
PubMed1991

A case of mucosal prolapse syndrome.

A case of mucosal prolapse syndrome in the rectum is reported. A 61-year-old female presented complaining of bloody discharge and constipation for 2 months. Colonoscopy revealed an elevated lesion on the left anterior wall of the rectal canal. Biopsy showed glandular proliferation and fibromuscular obliteration of the lamina propria, findings characteristic of mucosal prolapse syndrome. It is a rare disorder affecting the rectum because the lesion looks macroscopically like a protruding adenoma.

Adenoma↗
PubMed1991

[Effect of histamine on electrical properties in canine tracheal epithelium].

To characterize the action of histamine on ion transport across the airway mucosa, we measured the electrical properties of cultured tracheal epithelium from dogs by Ussing's short-circuited technique in vitro. The addition of histamine to the submucosal side increased short-circuit current (Isc), whereas mucosal addition of histamine had no effect. The histamine-induced increase in Isc was dose-dependent with the maximal increase from the baseline value and EC50 being 4.4 +/- 0.5 microA/cm2 and 10(-6) M, respectively. We also tested the effects of pharmacological blocking agents on the histamine-induced Isc increase. The effect of histamine on Isc was partially inhibited by pretreatment of cells with amiloride, furosemide and diphenylamine carboxylate. Furthermore, the effect of histamine was inhibited by pyrilamine, but not by cimetidine. To determine the contributions of several intracellular second messenger systems to the histamine-induced increase in Isc, we studied the change of Isc by pretreatment of cells with indomethacin, mepacrine and H-7. The increase in Isc produced by histamine was inhibited by indomethacin and mepacrine but not H-7. These results suggest that histamine stimulates both Cl secretion and Na absorption and may affect the subsequent movement of water across the airway epithelium through the activation of submucosal H1-receptor probably involving prostaglandin synthesis.

Animals↗
PubMed1991

[A late phase II study of CPT-11 on uterine cervical cancer and ovarian cancer. Research Groups of CPT-11 in Gynecologic Cancers].

A late phase II study of CPT-11, a new derivative of camptothecin, in uterine cervical cancer and ovarian cancer was carried out by a cooperative study group at 26 institutions. Out of 144 patients enrolled, total cases were 110, involving 55 uterine cervical cancers and 55 ovarian cancers. In uterine cervical cancer, 5 cases of complete response (CR) and 8 cases of partial response (PR) were observed, with a response rate of 23.6% and a CR rate of 9.1%. In ovarian cancer, 13 cases of PR were observed, response rate was 23.6%. Both in uterine cervical cancer and ovarian cancer, the 95% confidence interval of response rate was 12.4-34.8%. In cases having undergone previous chemotherapy including platinum, derivatives, the response rate in ovarian cancer was 23.1% (12/52). In cases of uterine cervical cancer having previous radiotherapy, the response rate was 26.8% (11/41). In ovarian cancer of various histological types, a response was observed for not only serous cystadenocarcinoma but also mucinous cystadenocarcinoma, etc. A response was observed in distant metastatic lesions such as lung metastasis as well as primary lesion in uterine cervical cancer and ovarian cancer. Major adverse reactions were leukopenia, nausea and vomiting, diarrhea and anorexia, and these incidences (grade 2 or more) were 87.3, 60.3, 44.0 and 67.2%, respectively. Since some patients experienced severe adverse reactions, caution should be taken in treatment with CPT-11. Besides these reactions, alopecia was observed (33.1%), but severe adverse reactions such as nephropathy were not found. No significant difference in the efficacy and adverse reactions were observed between administration methods; A, 100 mg/m2 once weekly and B, 150 mg/m2 once every 2 weeks. Both were thought to be clinically useful. These results suggest that CPT-11 is clinically effective against uterine cervical cancer and ovarian cancer.

Adult↗