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Biomedical subjects

N Takeuchi

Publications and source records attributed to N Takeuchi.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Chest radiograph of foreign bodies in the tracheobronchial tree].

Chest radiographs in 14 children with foreign bodies in the tracheobronchial trees were evaluated retrospectively. The most common causative materials were nuts, and both main bronchi were most commonly involved. The initial chest radiographs that were used for analysis were obtained one hour to 50 days after aspiration or onset of symptoms. Of the nine cases in which chest radiographs were taken within 7 hours after aspiration, six showed hyperlucency with (three cases) or without overinflation (three cases) in the affected lungs, and the other three showed normal chest radiographs. Two patients had indeterminate diagnoses on chest radiographs at inspiration: one patient underwent chest radiographs at expiration and the other underwent fluoroscopy. Air-trapping was demonstrated in both patients. Of another five cases in which chest radiographs were taken 18 hours after aspiration of a foreign body, three cases showed atelectasis or consolidation and the other two showed hyperlucent lung. From these observations, hyperlucent lung indicates an early stage of the disorder while atelectasis or consolidation indicates a fairly advanced stage. In patients with clinically suspected foreign bodies, we advocate that additional examinations be performed to establish a final diagnosis, even when chest radiographs are normal or indeterminate.

Bronchi↗
PubMed1991

The involvement of insulin in tryptamine-induced hypoglycemia in mice.

The effects of tryptamine on plasma glucose and serum insulin levels were studied in mice. Tryptamine elicited dose-dependent hypoglycemia and hyperinsulinemia in intact mice. In streptozotocin-diabetic mice, tryptamine did not change plasma glucose nor serum insulin levels. Tryptamine significantly inhibited glucose-induced hyperglycemia and enhanced insulin release elicited by glucose. These results indicate that tryptamine-induced hypoglycemia is brought on by its releasing effects of insulin.

Animals↗
PubMed1991

Pharmacological activities of the prenylcoumarins, developed from folk usage as a medicine of Peucedanum japonicum THUNB.

In connection with the chemical structure of coumarin 1 (a mixture of acetylangeloylkhellactone and acetyltigloylkhellactone), a compound isolated from Peucedanum japonicum THUNB., we synthesized eight coumarin compounds (3-10) and performed pharmacological studies on these nine compounds, as well as on another coumarin, praeruptorin A (= Pd-Ia) (2), a compound isolated from Peucedanum praeruptorum DUNN. We studied the effects of compounds 1-5 on isolated smooth muscle and of compounds 1-10 on the cardiovascular system. These compounds showed dose-related antagonistic effects on histamine- and Ca(2+)-induced contractions in smooth muscle and the potencies were in the order 2 greater than 1 greater than seselin (3) greater than xanthyletin (4) = 2.2.10-trimethyl-2H,8H-benzo[1,2-b: 3,4-b']dipyran-8-one (5). All the compounds except 7-geranyloxy-4-methylcoumarin (10) produced a dose-related increase in vertebral, carotid and femoral blood flow. Compounds 1, 5, and 4-methyl-7-(3-methyl-2-butenyloxy)coumarin (8) caused an increase in blood pressure, but 3 and 4 caused a slight decrease. Compounds 2, 3, 4, 5, and 8 increased heart rate. Jatamansinone (6) and jatamansinol (7) caused only slight changes in blood pressure. All the compounds except 10 increased heart rate. Compound 1 also increased blood flow in the cerebral cortex. Thus, compound 1 was confirmed to have an inhibitory effect on contraction in isolated smooth muscle and an action increasing arterial blood flow. Among the compounds tested in this study, 3, as well as 6 and 7 synthesized on the basis of 3, showed actions similar to those of Ca2+ blockers and some compounds had papaverine-like activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Cytotoxic acetylenes from Panax quinquefolium.

Three new cytotoxic polyacetylenes, PQ-1 (1), PQ-2 (2) and PQ-3 (3), have been isolated from Panax quinquefolium. The structures of these acetylenes were determined by analyses of their 1H-1H and 1H-13C COSY spectra. All these compounds exhibited strong cytotoxic activities against leukemia cells (L 1210) in tissue culture.

Acetylene↗
PubMed1991

Carcinoma of the esophagus: CT vs MR imaging in determining resectability.

MR imaging and CT were performed prospectively in 35 patients with esophageal carcinoma to determine the resectability of the primary tumors, because at our institution patients with resectable tumors have surgery regardless of the presence of distant metastases. Tumors with evidence of aortic or tracheobronchial invasion on MR or CT were considered to be unresectable. Tracheobronchial invasion was diagnosed when the tumor extended into the lumen of the airway, and aortic invasion was diagnosed when the triangular fat space between the esophagus, aorta, and spine adjacent to the primary tumor was obliterated. Two patients were excluded because of suboptimal MR images produced by motion artifacts. Pathologic proof was obtained from either surgery or autopsy in 31 patients. Of these, six patients (19%) had proved unresectable tumors (three aortic invasion and three tracheobronchial invasion). In all six cases, these features were correctly detected with both MR and CT. One patient had false-positive findings on MR and CT. An indeterminate diagnosis was obtained with MR in three patients and with CT in four patients. These incorrect or indeterminate results were all related to the diagnosis of aortic invasion. No patient had a false-negative result. When indeterminate diagnoses were considered false-positive, sensitivity, specificity, and accuracy for resectability were 100%, 84%, and 87%, respectively, for MR and 100%, 80%, and 84%, respectively, for CT. We conclude that MR and CT have nearly the same accuracy in predicting resectability of tumors in patients with esophageal carcinoma.

Adenocarcinoma↗
PubMed1991

[Blow-out fractures of the orbit--imaging modalities and therapeutic results].

Thirty-four cases of blow-out fracture were evaluated by high-resolution CT, Hess test for red and green color and synoptophore. The results of these tests were compared with the final outcome of the fractures. The fractures were classified on the basis of the location (floor, medial wall or roof), extent (total, partial or linear) and type of fragments (punched-out or trapdoor). The medial wall type included many cases (33%) with no complaint of double vision, and many cases with a combination of disturbances in ocular mobility in both the horizontal and vertical directions. The floor type showed a low incidence of disturbances in ocular movement in the horizontal directions. Regarding the extent of the fracture, all cases with the total type showed disappearance of double vision within three months. Many of the partial and linear types had a poor outcome. With regard to the type of fragments, all of the trapdoor type cases showed a favorable result with disappearance of double vision within three months. Some of the punched-out type cases, however, showed a poor outcome.

Adolescent↗
PubMed1991

[CT evaluation of the anterior epitympanic recess--comparison among non-inflammatory ear, chronic otitis media with central perforation and cholesteatoma].

The structures of the anterior epitympanic recess and its surrounding tissues were examined among non-inflammatory ear, chronic otitis media with central perforation and cholesteatoma, using axial scans of high resolution computed tomography. The length and width of the recess, as well as the number of the slices where the cog was determined, had no significant differences among them. Thus, the bony structure of the recess was considered to be seldom influenced by inflammatory processes. In the non-inflammatory ear, the degree of pneumatization around the recess was similar to that of the petrous apex cells and lower than that of the mastoid cells. In the chronic otitis media with central perforation and cholesteatoma, the pneumatization of the whole temporal bones was suppressed and the tendency was also found that the cells around the recess were less pneumatized than the mastoid cells. When cholesteatoma invaded into the anterior epitympanic recess, the destruction of the bony protrusion of the lateral wall between the recess and the epitympanum was recognized, as well as the disappearance of the cog. The bony protrusion was considered to be an inferior extension of the cog toward the anterior tympanic spine.

Cholesteatoma↗
PubMed1991

[The evaluation of cystoscopy in the screening of asymptomatic microhematuria].

As a prospective study on asymptomatic microhematuria, complete urological examinations including cystoscopy, IVP, ultrasound and urinary cytology were performed on 422 patients over 40 years old between January 1987 and December 1988 (group A). The results of group A was compared with that of retrospective study on 266 patients, who had incomplete urological examination between January 1984 and December 1985 (group B). Cystoscopy was performed on 321 patients (87.2%) in group A and on 108 patients (40.6%) in group B. Bladder tumor was found in 10 cases (2.4%) in group A, including 7 cases of male patients (5.7%), but in only 1 case (0.4%) in group B. Since the negative rate of abnormal urinary cytology was 50% and that of abnormal IVP was 90% in 10 cases of bladder tumor in group A, cystoscopy was considered to be an essential examination for the screening of patients with asymptomatic microhematuria over 40 years old patients.

Adult↗
PubMed1991

CT findings of endobronchial metastasis.

One hundred and sixty-one patients with pulmonary metastases were studied with CT. Six of them proved to have endobronchial (intraluminal) metastatic lesions by bronchoscopy. Retrospective analysis of the CT studies showed obstruction and/or narrowing of the bronchi in 5 cases while no lesion was observed in one patient. Although CT can not always demonstrate intraluminal lesions, it should be performed when an endobronchial metastasis from extrathoracic malignancy is seen by bronchoscopy because it will show hilar or mediastinal lymphadenopathy, or single or multiple pulmonary metastases other than the endobronchial lesion.

Adult↗
PubMed1991

[Distribution of ciclosporin in the lymphoid tissue].

To clarify the distribution and the kinetics of ciclosporin (CSA) in the lymphatic system, we measured the CSA level of the lymph from the thoracic duct drainage (TDD) and that of the peripheral blood after oral or intravenous administration of CSA in 13 TDD pretreated patients. We also measured the CSA level of the iliac lymph nodes in 20 patients undergoing transplant surgery. The mean CSA level of the lymph was 1,647 ng/ml in the first 2 hours, 1,551 mg/dl in the next 10 hours and 254 ng/dl in the last 12 hours in orally administered patients and the mean CSA level of the peripheral blood was 746 ng/ml at 2 hours, 263 ng/ml at 12 hours and 119 ng/ml at 24 hours later. In intravenous administration, the mean CSA level of the lymph was 68 ng/ml, 58 ng/ml and 33 ng/ml and the mean CSA level of the peripheral blood was 452 ng/ml, 105 ng/ml and 88 ng/ml respectively. The mean CSA level of the lymph node was 3,222 ng/g and the mean diffusion rate from the peripheral blood to the lymph node was 17.1. There was no difference between oral and intravenous administration. These results indicated that (1) there is a second pathway in which orally administered CSA is transported from small bowel to general circulation; via mesenteric lymph duct, thoracic duct and subclavic vein and (2) CSA is selectively uptaken by lymph node. CSA might suppress the activation of T cells in the lymph node and the lymph more effectively than in the peripheral blood.

Administration, Oral↗
PubMed1991

[Metabolic disorders of lipoproteins--influences of compositional changes of lipoproteins upon their metabolic behavior].

Compositional changes of apoproteins and lipids in lipoproteins influence their affinities for receptors and enzymes. Decrease of apo C proteins and increase of apo E in chylomicron and very low density lipoproteins (VLDL) during their catabolism might promote the binding to remnant receptor. On the other hand, the affinity for lipoprotein lipase (LPL) gradually decreases and that for hepatic lipase increases. However, the responsiveness of VLDL to LPL might be under the control of triglyceride (TG)/surface component ratios but not of the apoprotein ratios in ordinary circumstances judging from the results of the releases of fatty acids from VLDL by LPL in vitro. Responses of VLDL from diabetic patients to LPL significantly decreased compared with those from non-diabetic subjects. Glycation of VLDL in vitro impaired their responses to LPL. Therefore, delayed catabolism of VLDL in diabetes might partially depend upon glycation of VLDL besides the decreased LPL activity. Low density lipoproteins (LDL), apoproteins of which consist mostly of apo B protein and had a low TG level, showed a high affinity to the LDL receptor. However, LDL from hypertriglyceridemic subjects, in which the TG contents was increased, had a low affinity to the receptor. Since high density lipoproteins (HDL) from patients in acute phases contain a large amount of serum amyloid A protein (SAA), the percentages of apo A proteins markedly decreased. When SAA-rich HDL were incubated with leucocytes, SAA were degraded rapidly, although other apoproteins remained to be unchanged. Therefore, such HDL become unstable, and this might induce low HDL levels in the acute phase.

Apoproteins↗
PubMed1990

The activation of serotonin receptors by tryptamine induces hyperinsulinemia in mice.

The effects of tryptamine on serum insulin levels were investigated. Tryptamine induced an apparent increase in serum insulin levels in mice. The elevation in insulin elicited by tryptamine was potently antagonized by the 5-HT1 and 5-HT2 receptor antagonist, methysergide, but partially reduced by the 5-HT2 receptor antagonist, ketanserin. However, the 5-HT3 receptor antagonist, ICS 205-930, was without effect. These results indicate that both 5-HT1 and 5-HT2 receptors are involved in the tryptamine-induced increase in insulin levels.

Animals↗
PubMed1990

Radiation inactivation target-size analysis of soluble guanylate cyclase.

The soluble form of guanylate cyclase, which is a heterodimer of two subunits with molecular weights of 82,000 and 70,000, was analyzed by radiation inactivation experiments to determine its functional size. Lyophilized crude extract from rat lung or the purified enzyme were irradiated with different doses from 60Co gamma-rays, and the residual activities were measured in the presence or absence of a potent activator, sodium nitroprusside. The target sizes for the basal activity and for the activity in the presence of sodium nitroprusside were calculated from the decay curve was 77 and 192 kDa, respectively, on the crude enzyme, or as 71 and 163 kDa, respectively, on the purified enzyme. The size for the activatable form of the enzyme was more than twice that of the basal activity and close to the size of the holoenzyme, implying that the enzyme activity must reside on one of the subunits and the activation by sodium nitroprusside requires interaction of both subunits.

Animals↗
PubMed1990

An outlet obstruction caused by V-shaped bar at the bladder neck in a woman.

A case of outlet obstruction caused by a V-shaped bar at the bladder neck in a woman was treated successfully by transurethral resection of the bar. The poor urinary flow in our patient was believed to be due to impedance during voiding caused by retraction of the bladder neck in the anteroposterior direction by the bar. Our case is different from previously reported cases.

Cystoscopy↗
PubMed1990

Effect of vitamin C depletion on serum cholesterol and lipoprotein levels in ODS (od/od) rats unable to synthesize ascorbic acid.

The effect of ascorbic acid deficiency on serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoprotein levels and serum lipoprotein cholesterol levels were examined in male rats with a hereditary defect in ascorbic acid synthesis (ODS rats). Male homozygotes (od/od) and male rats of their parent strain (+/+) were each divided into four treatment groups and were fed vitamin C-deficient or vitamin C-replete diets containing either 0 or 0.5% cholesterol. During the 3-wk feeding-period the ODS (od/od) rats fed the vitamin C-deficient diet gradually decreased food intake, resulting in a lower body weight than that of od/od rats given ascorbic acid. The serum cholesterol level was significantly higher in the vitamin C-deficient od/od rats fed the cholesterol diet, and it tended to be higher in those fed the control (0% cholesterol) diet, whereas the liver lipid levels remained unchanged relative to those in od/od rats fed the vitamin C-replete diet. The serum very low density lipoprotein and high density lipoprotein (HDL) cholesterol levels were lower in od/od rats fed the vitamin C-deficient diet without cholesterol, but intermediate density lipoprotein and low density lipoprotein cholesterol levels were markedly higher in the vitamin C-deficient od/od rats than in od/od rats given ascorbic acid, regardless of dietary cholesterol level. The ratio of HDL2 cholesterol to HDL3 cholesterol was also higher in the vitamin C-deficient od/od rats. The parent strain of the od/od rats (+/+) showed no change due to vitamin C deficiency. These results suggest that vitamin C deficiency delays low density lipoprotein metabolism and produces hypercholesterolemia in male od/od rats.

Animals↗
PubMed1990

Primary structure of a fucose-specific lectin obtained from a mushroom, Aleuria aurantia.

Aleuria aurantia lectin (AAL) is a protein composed of two identical subunits having no carbohydrate chain and shows sugar-binding specificity for L-fucose. Full-length cDNA encoding for the lectin has been isolated from a lambda gt11 library, screened with an antiserum directed against AAL. The cDNA clone contained 1,370 nucleotides and an open reading frame of 939 nucleotides encoding 313 amino acids. The amino-terminal sequence (residues 1-30) of the lectin isolated from the mushroom coincided with the deduced amino acid sequence starting from proline at the 2nd residue, indicating that the mature AAL consists of 312 amino acids. Its molecular weight is calculated to be 33,398. The deduced amino acid sequence shows that AAL includes six internal homologous regions, and has considerable homology with a hemagglutinin from a Gram-negative bacterium, Myxococcus xanthus, which forms a fruiting body. No significant homology was observed with higher plant or animal lectins. The recombinant AAL produced by Escherichia coli JM109 carrying the AAL expression plasmid pKA-1 [Fukumori, F. et al. (1989) FEBS Lett. 250, 153-156] was purified from the cell lysate by affinity chromatography using a fucose-starch column, and hundreds of milligrams of the lectin was obtained. The recombinant lectin showed the same biochemical characteristics and sugar binding specificity as did the natural AAL.

Amino Acid Sequence↗
PubMed1990

Synthesis and absolute configurations of the cytotoxic polyacetylenes isolated from the callus of Panax ginseng.

Panaxacol (1) and dihydropanaxacol (2), cytotoxic polyacetylenes isolated from the callus of Panax ginseng, were synthesized starting from D-(-)-diethyl tartrate. The absolute configuration of 1 was determined to be 9R, 10R and the absolute configuration at C-3 of 2 was tentatively assigned as 3S by the application of the R(+)-alpha-methoxy-alpha-(trifluoro methyl)phenylacetyl (MTPA) method.

Alkynes↗