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Biomedical subjects

T Naito

Publications and source records attributed to T Naito.

At least 217 records · Page 12Linked to original sources
PubMed1992

[A case of cardiac lipoma of the anterior tricuspid leaflet].

A 42-year-old man with cardiac lipoma of the anterior tricuspid leaflet is reported. He had a chief complaint of epigastric discomfort, and a pansystolic murmur was heard at the left sternal border in the 4th intercostal space. Two-dimensional echocardiography disclosed a mobile high density stalkless mass having several areas of low density. Two-dimensional Doppler echocardiogram revealed a moderate degree of tricuspid regurgitation. These findings were more clearly visualized on transesophageal echocardiogram. MRI revealed a high signal intensity on the T1-weighted image and a high radiodensity surrounding the mass using a contrast medium of Gd-DTPA. A 2.0 x 1.3 x 0.8 cm hemispherical, lobulated and sessile yellow mass was excised by means of open heart surgery, and tricuspid valvuloplasty was performed. The mass was adipose tissue and was surrounded by fibrous tissue just under the lamina fibrosa. These findings were compatible with those of the preoperative examinations, although the preoperative diagnosis was not conclusive. This was our first case of cardiac lipoma in which the tricuspid valve was successfully excised.

Adult↗
PubMed1991

Determination of beta-carbolines in foodstuffs by high-performance liquid chromatography and high-performance liquid chromatography-mass spectrometry.

A high-performance liquid chromatographic method combined with fluorimetric detection is described for the determination of beta-carboline (norharman) and 1-methyl-beta-carboline (harman). The analysis of foodstuffs for the identification of beta-carbolines is facilitated by clean-up samples using Bond Elut PRS cartridges. Recoveries were excellent. Further, a high-performance liquid chromatographic-mass spectrometric method was also developed for their identification. The concentration of beta-carboline among the foodstuffs and alcoholic beverages varied greatly. Also, norharman and harman were observed in uncooked foodstuffs, whereas acetaldehyde was found in most fermented food. The toxicological implication of beta-carbolines in foodstuffs is discussed.

Acetaldehyde↗
PubMed1991

Ion-sparing diuresis by 2,3-dibenzylbutane-1,4-diol, a synthetic mammalian-lignan derivative.

Diuretic properties of a synthetic lignan, 2,3-dibenzylbutane-1,4-diol (hattalin), and a naturally occurring arctigenin were examined in BALB/c male mice and Wistar male rats. Intra peritoneal administration of hattalin (50 mg/kg) in mice increased urine volume by 1.7-3.1 fold that of placebo-treated animals 40-260 min after administration (p less than 0.05 vs control). In contrast, 100 mg/kg of arctigenin had no effect on urine volume in mice. Hattalin (100 mg/kg), arctigenin (100 mg/kg), or furosemide (50 mg/kg) as a positive control was administered orally to rats, and accumulated urine volume was measured for up to 6-12 h. The urine volume of animals administered with hattalin showed 1.4-1.5 fold that of placebo-treated animals after 2-6 h of administration (P less than 0.05, n = 10). On the other hand, arctigenin showed no significant effect on urine volume for up to 12 h after administration (n = 8). The urine volume in animals administered with furosemide (n = 10) was 2.0-3.0 fold that of placebo-treated animals (P less than 0.01). Furosemide increased total Na+, K+, or Cl- excretion by 1.9, 1.8 or 2.2 fold, respectively, when compared with placebo-treated controls (P less than 0.01), whereas hattalin decreased Na+ excretion by 3.6 times (P less than 0.01), K+ excretion by 1.4 times (not significant), and Cl- excretion by 3.1 times (P less than 0.01). Serum Na+ and K+ levels did not change in both furosemide- and hattalin-administered rats, however, serum Cl- levels in these animals significantly decreased (P less than 0.01) when compared with controls. The results suggest that the diuretic property of hattalin is due to a novel mechanism which is different from that of furosemide or other diuretics modifying the ion-exchange at the uriniferous tubules.

Animals↗
PubMed1991

Identification of tetrahydro-beta-carboline-3-carboxylic acid in foodstuffs, human urine and human milk.

1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) and 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (TCCA), both precursors of mutagenic N-nitroso compounds (N-nitrosamines, 1-methyl-2-nitroso-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid and 2-nitroso-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid), were detected in various food-stuffs, urine from healthy human subjects and human milk. A purification procedure, involving a chemically-bonded material followed by HPLC combined with fluorometric detection, was used for the quantitative determination of these compounds, allowing the separation of two diastereoisomers of MTCA. An HPLC and mass spectrometry method was also developed for their identification. Comparing the concentration of MTCA and TCCA in fermented products and raw materials suggested that tetrahydro-beta-carbolines may have been produced through fermentation or by condensation of tryptophan and acetaldehyde formed from ethanol added as a food preservative. This is the first report of excretion of tetrahydro-beta-carbolines in human urine and human milk. A comparison of the concentrations of tetrahydro-beta-carbolines in urine from human infants and human milk indicates that tetrahydro-beta-carbolines may be synthesized endogenously in humans. A possible pathway of tryptophan metabolism in plants and animals is presented.

Adult↗
PubMed1991

Well-differentiated hepatocellular carcinoma showing intrahepatic neural invasion: autopsied case.

An autopsied case of well-differentiated hepatocellular carcinoma (HCC), showing neural invasion into the portal tract of the liver, a hitherto undescribed lesion, is reported. The patient, a 68-year-old man, had had treatment for HCC over nine years, comprising surgical resection, transcatheter arterial embolization, transportal venous embolization and percutaneous ethanol injection to nodules of the HCC. At autopsy, many HCC nodules (less than 7 cm in diameter) were found in the liver. In one of them, carcinoma cells infiltrated the medium-sized protal tract among the regenerative nodules and some of these carcinoma cells further invaded nerve fibers. Although the majority of the HCC nodules showed ischemic necrosis, the infiltrating carcinoma cells in the portal tract were viable, suggesting the biological behavior and/or blood supply of these infiltrating carcinoma cells to be different.

Aged↗
PubMed1991

Caries susceptibility in inbred mouse strains and inheritance patterns in F1 and backcross (N2) progeny from strains with high and low caries susceptibility.

We studied dental caries susceptibility in various inbred mice strains infected with Streptococcus mutans and the inheritance pattern in the F1 and the N2 backcross animals. A high caries score was observed in four laboratory strains, BALB/cAJcl, C57BL/6NJcl, C57BL/10Slc and DBA/2NJcl. Three strains, C3H/HeNJcl, AKR/JSlc and CBA/JNCrj, showed less caries. Males of strain C57BL/10Slc (mean caries score = 112.2) and females of strain C3H/HeNJcl (mean caries score = 24.0) were chosen for examinations of the inheritance of the caries susceptibility. The mean caries score in (C57BL/10Slc x C3H/HeNJcl) F1 hybrids was 98.4, demonstrating that F1 progenies were susceptible. A number of N2 mice were obtained by mating the F1 male and the C3H/HeNJcl female. The caries scores of these N2 male mice had an extensive range, from 14 to 194. Assuming that a caries score over 74 (median of the scores between C57BL/10Slc and C3H/HeNJcl) belonged to the highly caries-susceptible group, N2 mice could be divided into groups with low or high caries susceptibility. Furthermore, the effect of nu/nu mutation on caries susceptibility in mice was also examined.

Analysis of Variance↗
PubMed1991

Development of active center-directed inhibitors against plasmin.

Active center-directed inhibitors of plasmin were designed based on the structure of specific substrates of plasmin and then synthesized. Their effects on plasmin were examined and the structure-inhibitory activity relationship was studied. N alpha-trans-4-Aminomethylcyclohexanecarbonyllysine 4-benzoylanilide (Tra-Lys-BZA) inhibited plasmin activities toward S-2251 and fibrin with IC50 values of 15 and 6.1 microM, respectively and N alpha-trans-4-aminomethylcyclohexane-carbonyllysine 4-benzylpiperidine amide (Tra-Lys-BPP) did not show any detectable inhibitory activity. Moreover, it was revealed that Tra-Lys-4-methoxycarbonylanilide inhibited plasma kallikrein more potently than plasmin.

Binding Sites↗
PubMed1991

Development of selective inhibitors against plasma kallikrein.

Specific plasma kallikrein inhibitors were designed and synthesized and their structure-activity relationship was studied. trans-4-Aminomethylcyclohexanecarbonyl (Tra)-lysyl-4-ethoxycarbonylanilide inhibited plasma kallikrein and plasmin with IC50 values of 23 and 210 microM, respectively, indicating that this compound is fairly specific to plasma kallikrein. Tra-arginyl-4-ethoxycarbonylanilide inhibited plasma kallikrein and plasmin with IC50 values of 16 and 480 microM, respectively. Tra-homoarginyl-4-carboxyanilide inhibited plasma kallikrein and plasmin with IC50 values of 14 microM and 1 mM, respectively. Finally, Tra-Arg(Mts)-4-acetylanilide (ACA) exhibited potent and selective inhibitory activity against plasma kallikrein (IC50 value for plasma kallikrein: 2 microM and for plasmin: 42 microM).

Amino Acid Sequence↗
PubMed1991

Interpersonal relations and helping norms among university students of Japan, Taiwan, and Korea.

This study investigated the effects of interpersonal relations on some aspects of moral judgment among 68 Japanese, 70 Chinese, and 92 Korean university students. The subjects were asked to judge agents' acts in stories about varied helping situations which formed a factorial design: familiarity and kinship between subjects and the agent, those between the agent and the victim, and actions. Analysis showed that the two relationships between the agent and the victim significantly affected judgments in three cultures. The magnitudes of the effects of kinship between agent and victim varied across the cultures.

Adult↗
PubMed1991

Effects of 9-(1,3-dihydroxy-2-propoxymethyl) guanine (DHPG) eye drops and cyclosporine eye drops in the treatment of herpetic stromal keratitis in rabbits.

The effect of 9-(1,3-dihydroxy-2-propoxymethyl) guanine (ganciclovir, DHPG) eye drops and the anti-inflammatory effect of cyclosporine (CYA) eye drops on experimental herpetic stromal keratitis in rabbits with herpes simplex virus (HSV) were studied. Ten rabbits were presensitized by subcutaneous injection of HSV, type 1, on days 14 and 7 before intrastromal inoculation of the same virus. These rabbits were divided into 2 groups and treatment was started 48 hours after virus inoculation. The eye drops used were 0.1% DHPG, 0.1% CYA or the vehicles of these eye drops. Eye drops were given 5 times a day and eyes were scored every day for 3 weeks after inoculation. The right eyes of Group 1 were treated with 0.1% DHPG and 0.1% CYA eye drops, and the left eyes with 0.1% DHPG and the vehicle of CYA eye drops. The right eyes of Group 2 were treated with 0.1% CYA and the vehicle of DHPG eye drops, and the left eyes with the vehicles of CYA and DHPG eye drops. The combination of DHPG and CYA was the most effective in decreasing the severity of herpetic stromal keratitis. Treatment with DHPG alone was also effective, but CYA alone was less effective.

Administration, Topical↗
PubMed1991

Synthesis and biological activity of 1-N-[4-(substituted)amidino and guanidino-2-hydroxybutyryl]kanamycins A and B.

The synthesis and biological properties of 1-N-[4-(substituted)amidino and guanidino-2-hydroxybutyryl]kanamycins A and B are described. Reaction of 3,3",6'-tri-N-tert-butoxycarbonyl-amikacin with an appropriate amidinating or guanidinating reagent and subsequent deblocking gave a series of amikacin derivatives having an amidino or guanidino group on the 4"'-position. The corresponding kanamycin B analogs were also prepared by a similar procedure. Among these derivatives, 1-N-(4-formamidino- and guanidino-2-hydroxybutyryl)kanamycins A (7a and 7k) and B (11 and 14) exhibited antibacterial activity similar to the corresponding 4-amino analogs. The nephrotoxic potential of selected compounds is also briefly discussed.

Animals↗
PubMed1991

Synthesis and activity of butirosin derivatives with 5''-amidino and 5''-guanidino substituents.

The preparation and antibacterial activity of the 5''-guanidino (6) and 5''-amidino (7) derivatives of 4'-deoxybutirosin A (1) as well as the 5''-guanidino derivative (8) of butirosin A are described. The key intermediates, tetra-N-benzyloxycarbonyl-5''-azido derivatives were selectively reduced with NiCl2-NaBH4 to give the corresponding 5'-amino derivatives. Subsequent guanidination or amidination followed by deblocking afforded the final compounds 6, 7 and 8. The 5''-guanidino derivatives (6 and 8) were more active against Gram-positive and Gram-negative bacteria than the corresponding 5''-hydroxy derivatives (1 and butirosin A). Compound 6 was also active against a variety of methicillin-resistant Staphylococcus aureus (MRSA).

Animals↗
PubMed1991

[Clinical characteristics of precordial ST-segment depression in acute inferior myocardial infarction].

Assessments of the significance of precordial ST segment depression in acute inferior myocardial infarction (AIMI) have yielded conflicting results. Among 92 AIMI patients admitted within 6 hrs after the onset, 65 showed ST depression, and the remaining 27 showed no ST depression. These depressions were present in all of V1-4 (right type; 17), V2-5 (middle type; 10), V3-6 (left type; 13) and V1-6 (broad type; 25). The clinical severity was Forrester subset I in the majority (89%) of patients without ST change, while complications were prevalent in patients with ST depression, especially in the right type (44% were Forrester subset II-IV). Peak CK was 2,150 +/- 399 U/L in patients without ST depression, but it was elevated to 3,172 +/- 811 in patients with ST depression, especially in the right type (4,506 +/- 499). Wall motion evaluated by echocardiography and QRS scores on ECG also revealed greater abnormality in patients with ST change. The initial right coronary angiogram on admission revealed complete occlusion in 76% of these patients with ST depression of whom all of the right type had completely occluded artery. Abnormal motion of the anterior wall, which suggests remote ischemia associated with AIMI was proved neither by left ventriculography nor echocardiography. Hospital mortality in patients with ST depression (9.2%) was as twice as high as that in those without ST depression (4.6%). We concluded that ST depression in patients with acute inferior infarction may not be indicative of remote ischemia but manifests as a mirror image of a large infarction with a complicated clinical course.

Adult↗
PubMed1991

[Energy index of heart rate spectral analysis for the assessment of autonomic nerve activities].

Heart rate spectral analysis was performed in 17 male healthy volunteers by changing their positions (supine or standing) and respiratory rates (8, 10, 12, 15 and 20 bpm). Furthermore, analysis was made by a multiple regression method on parameters such as R-R interval, tidal volume, respiratory time and positions of the subjects which may contribute to the peak power values of high frequency components (HFC, synchronous with respiratory patterns and of low frequency components (LFC, about 0.1Hz). HFC power was found to be significantly dependent on R-R interval and respiratory time, but not on tidal volume or position. Following equation was obtained. HFCP = 11.3 X RTX (RR-0.246) HFCP: HFC power value (msec) RT: respiratory time (sec) RR: R-R interval (sec) Therefore, HFCP or area under the curve (AUC) of HFC is not appropriate for the assessment of autonomic nerve activities, especially when respiratory rate or heart rate is changing. The intensity of physical wave is in proportion to (amplitude X frequency). Consequently, in a case where frequency is changeable, (amplitude X frequency) is a good index of the oscillatory energy. Therefore, sigma (power X frequency) is proposed as a suitable index for a certain component of power-spectrum. Parasympathetic activity should be assessed by the following index induced from the previously mentioned equation. RR adjusted HFEI (high frequency energy index) = sigma (power X frequency)/(RR-0.246) (0.15Hz less than frequency less than 0.4Hz). Similarly, low frequency components which reflect the sympathetic activity should be assessed by the following equation. LFEI (low frequency energy index) = sigma (power X frequency) (0.05Hz less than frequency less than 0.15Hz). The assessment of autonomic nerve activities becomes more appropriate by using these indices especially when heart rate and respiratory rate are changing.

Adult↗
PubMed1990

Effect of a highly selective plasma-kallikrein synthetic inhibitor on contact activation relating to kinin generation, coagulation and fibrinolysis.

A highly selective inhibitor of plasma-kallikrein (PK), N-(trans-4-aminomethylcyclohexylcarbonyl)-L-phenylalanine 4-carboxymethyl-anilide hydrochloride, was designed and synthesized by the authors' group, called PKSI-527 in our laboratories. (I) PKSI-527 inhibited PK with a Ki value of 0.81 microM. By contrast, the Ki values for glandular kallikrein (GK), plasmin, thrombin, urokinase and factor Xa were greater than 500 microM, 390 microM, greater than 500 microM, 200 microM and greater than 500 microM, respectively. (II) Effects of PKSI-527 on bradykinin (BK) generation, coagulation and fibrinolysis by contact activation were examined using human plasma. (a) BK generation induced by kaolin appeared to be reduced by PKSI-527. Furthermore BK generation induced by lambda-carrageenan, a strong inflammatory agent, was also reduced by PKSI-527. (b) Partial thromboplastin time (PTT) was prolonged by PKSI-527, indicating the suppression of the intrinsic coagulation system. (c) Euglobulin clot lysis time (ECLT) of plasma which was shortened by activation with kaolin, was prolonged by the addition of PKSI-527, confirming the participation of PK in contact-fibrinolysis. These results indicate that PKSI-527 shows great potential in elucidating the significance of PK, and as such deserves further investigation.

Blood Coagulation↗
PubMed1990

Multifocal neurilemomas in different nerves of the same upper extremity.

We report a case of multifocal neurilemomas originating from different nerves in the same upper extremity. In the excision of all seven tumors care was taken not to damage the nerves involved. The common features of multifocal neurilemomas that originated from different nerves of the same upper extremity are outlined and the consequent risk of potential nerve damage during the operation is discussed. We recommend intracapsular excisions of multifocal neurilemomas.

Humans↗