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Biomedical subjects

M Moriguchi

Publications and source records attributed to M Moriguchi.

At least 73 records · Page 4Linked to original sources
PubMed1991

Microvasculature of the tympanic membrane.

In order to investigate the blood flow of the tympanic membrane (TM) in various conditions, the microvasculature of the TM was observed by scanning electron microscope, using casting methods. Differences in vascular patterns between pars tensa and pars flaccida were observed, suggesting that vascular distribution in TM is closely concerned with the arrangement of radial fibers in the intermediate fibrous layer. Once inflammation was induced, changes in blood vessels quickly took place and most remarkably at the central zone of TM. The TM which closed earlier was found to leak resin at the edge of the perforation. It is proposed that an active blood flow to the perforation edge is necessary for a smooth closing.

Animals↗
PubMed1991

Microvascular structure of the larynx. A scanning electron microscopic study of microcorrosion casts.

In this study, scanning electron microscopic observations were made of the microvasculature of the larynx of guinea pigs, rabbits and humans. The results showed that 1) The epiglottis being the most abundant of all laryngeal structures in vascular plexus, with some of the vessels perforating cartilage; 2) Blood vessels of the vocal cord course along its long axis showing undulation; arteriovenous anastomoses was noted; 3) In the arytenoid, blood vessels were found to be irregularly coursing and tortuous, thereby facilitating the purpose of smooth movements of this structure.

Animals↗
PubMed1991

Structure of aureobasidin A.

Aureobasidin A, a new antifungal antibiotic, was isolated from the culture medium of Aureobasidium pullulans R106. Aureobasidin A was a cyclic depsipeptide consisting of eight alpha-amino acid units and one hydroxy acid unit. The structures of the units were found by acid hydrolysis of the antibiotic to be 2(R)-hydroxy-3(R)-methylpentanoic acid, beta-hydroxy-N-methyl-L-valine, N-methyl-L-valine, L-proline, allo-L-isoleucine, N-methyl-L-phenylalanine, L-leucine, and L-phenyl-alanine. The sequence of the units was identified by NMR and FAB-MS of the products from the alkaline hydrolysis of aureobasidin A.

Amino Acid Sequence↗
PubMed1990

Magnetic resonance imaging of experimental rat brain tumors: histopathological evaluation.

Using RG-C6 glioma-transplanted rats, we studied precontrast and postcontrast magnetic resonance imaging, extravasation of Evans blue, and histology. In all rats, tumor was enhanced with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA). The necrotic portion in the tumor, however, was not enhanced. Hemorrhage and hydrocephalus were clearly visualized on both the precontrast and postcontrast images. Blood-brain barrier-disrupted areas stained with Evans blue and areas enhanced with Gd-DTPA on magnetic resonance imaging were nearly consistent. It is suggested that the mechanism of brain tumor enhancement with Gd-DTPA on magnetic resonance imaging is simply related to the degree of alteration of the blood-brain barrier. The Gd-DTPA-enhanced magnetic resonance imaging, even with low magnetic field, is useful for the evaluation of size, shape, and location of experimental rat brain tumors.

Animals↗
PubMed1990

[Experience in the use of Kyosera Injection Port as a kind of implantable reservoir (the second report)].

A total of 30 pieces of Kyosera Injection Port, as a kind of implantable reservoir, was used in 29 cases of liver tumor for an intermittent repeated chemotherapy. Of these 27 cases were actually used between Aug. 1st, 1986 and Aug. 31st, 1989. In this paper we studied the safety of the reservoir. The observation period averaged 259.4 days, with the highest of 760 days and the lowest of 29 days. The injection times averaged 12.7 times, with the maximum of 40 times and the minimum of one. The reservoir was placed under the laparotomy, and the cases which underwent cholecystectomy were 93.1%. 16 cases were treated with intraarterial infusion, and 14 with intraportal infusion. We investigated the complication of Kyosera Injection Port in 27 cases. As a result, there were no complication such as catheter occlusion and infection via catheter. But of 27 cases, 8 cases were recognized a complication, and the rate was 29.6%. Lumbago was noted during infusion chemotherapy in three cases, and on the other hand, there were steatolysis and necrosis of the tissue surrounding the implantation site, a movement of port, a catheter out of vessel, a leakage of the drug, and intraabdominal bleeding after taking off the catheter. But of 8 complication cases, only two cases were not able to inject drug. As a result, the rate of complication was 70.4% in over all. On the other hand, of 27 cases, there were 5 cases which recognized the complication caused by reservoir in itself. The safety rate was 81.5%. In such a circumstance this reservoir was very safe and seemed suitable to the implantable reservoir.

Adult↗
PubMed1988

Production of d-Aminoacylase from Alcaligenes denitrificans subsp. xylosoxydans MI-4.

A bacterial strain that produces d-aminoacylase was isolated from soil and identified as Alcaligenes denitrificans subsp. xylosoxydans MI-4. l-Aminoacylase activity in this strain was only 1 to 2% of d-aminoacylase activity. d-Aminoacylase was inducibly produced. N-Acetyl-dl-leucine was the best inducer, and the d-isomer had the ability to induce the enzyme. Enzymatic resolution of N-acetyl-dl-methionine with the crude enzyme was carried out, and the d/l ratio in the resolved methionine was approximately 100/7, suggesting that resolution with crude enzymes may become possible by removing small amounts of the contaminated l-form with l-amino acid oxidase.

Journal Article↗
PubMed1988

Synthesis of histargin and related compounds and their inhibition of enzymes.

A novel method for the synthesis of histargin and its analogs is described. It includes two kinds of N-alkylation reactions that prevent the formation of side products. The inhibition of enzymes by these compounds was also measured. Some of the compounds strongly inhibited carboxypeptidase B, carboxypeptidase A, carboxypeptidase N (kininase I), and angiotensin converting enzyme.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1987

The effect of dietary seaweeds on 7,12-dimethyl-benz[a]anthracene-induced mammary tumorigenesis in rats.

Six groups of female rats were fed diets containing 2% of one of six powdered seaweeds for 152 days and a basic diet for 59 or 60 successive days, and controls were fed the basic diet for the whole experimental period. The 7,12-dimethylbenz[a]anthracene was given to all rats intragastrically (20 mg/kg X 1), 27 days after the start of feeding. Diets with 3 weeds, Porphyra tenera (PT), Laminaria religiosa (LR) and L. japonica var. ochotensis (LO), showed an inhibitory effect on mammary tumorigenesis. Tumor incidences were 35% (7/20), 35% (7/20) and 50% (9/18), respectively, whereas that in the control group was 69% (20/29). There was a significant delay in the time to first palpable tumor in LR-fed and PT-fed rats (P less than 0.01). As for the tumor weight per rat in each group, it was significantly lower in the LR-fed group with a weight of 1.6 g, as compared with that of 16.3 g in the control group (P less than 0.02).

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Synthesis and antitumor activity of spergualin analogues. II. Chemical modification of the spermidine moiety.

Chemical modifications of the spermidine moiety of an antitumor antibiotic, spergualin (Ia), and the structure-activity relationship are described. Replacement of spermidine with other polyamines decreased the antitumor activity against mouse leukemia L1210. Analogues containing an oxidized spermidine moiety that probably formed during oxidation with amine oxidase were inactive. Spermidine is indispensable for the antitumor activity. A facile method for the synthesis of glyoxyloyl polyamine, a key intermediate of spergualin-related compounds, is also reported.

Animals↗
PubMed1987

Synthesis and antitumor activity of spergualin analogues. III. Novel method for synthesis of optically active 15-deoxyspergualin and 15-deoxy-11-O-methylspergualin.

Optically active 15-deoxyspergualin (II) and 15-deoxy-11-O-methylspergualin (IIa) were synthesized, and their antitumor activities were examined. The (-)-enantiomers of both II and IIa were active against mouse leukemia L1210, while the (+)-enantiomers were almost inactive. The optical resolution of the key intermediate, (+/-)-N-(7-guanidinoheptanoyl)-alpha-alkoxyglycine (VI) was achieved by use of an exopeptidase, serine (acid) carboxypeptidase [EC 3.4.16.1] and (+/-)-N-(7-guanidinoheptanoyl)-alpha-alkoxyglycyl-L-amino acid (VIII) as the substrate. Considering the enzymatic susceptibility of the substrate (VIII), we deduced that the absolute configuration of the carbon at 11 (C-11) of the bioactive (-)-enantiomer, and so that of natural spergualin (I), is S. This is, to our knowledge, the first report of the use of carboxypeptidase for the resolution of N-acyl amino acid.

Animals↗
PubMed1986

Prevention of caffeine-induced limb malformations by maternal adrenalectomy.

Caffeine at high doses is a known rodent teratogen and induces limb malformations along with cleft palate in various strains of rats and mice. Fujii and Nishimura ('74) postulated that caffeine was teratogenic by virtue of catecholamine release from maternal or embryonic tissue. We tested this hypothesis by surgically removing the maternal adrenal gland on day 6 of pregnancy and then administering 175 mg/kg of caffeine intraperitoneally at 1600 h day 11 and 900 h day 12. The teratogenic effects of caffeine in adrenalectomized versus nonadrenalectomized AKR mice were assessed in day 18 fetuses. Thirty percent of the surviving offspring were malformed in caffeine-treated, nonadrenalectomized dams compared to 7% of the offspring from adrenalectomized dams. Therefore we believe caffeine teratogenesis is initiated by release of catecholamines from the maternal adrenal gland.

Adrenal Glands↗
PubMed1986

Partial purification and properties of gamma-glutamyltranspeptidase from mycelia of Morchella esculenta.

Three gamma-glutamyltranspeptidase (enzymes I, II and III) were partially purified from the cell free extracts of the cultured mycelia of Morchella esculenta Fr. The molecular masses of enzymes were 155,000 (I), 219,000 (II) and 102,000 (III). All of them catalyzed both hydrolysis and transpeptidation of various gamma-glutamyl compounds. gamma-L-Glutamyl-cis-3-amino-L-proline occurring in the cultured mycelia of this fungus was a good substrate for both reactions. Km values for hydrolysis were in the order of 10(-4) to 10(-5) M, and those for transpeptidation were in the order of 10(-2) to 10(-4) M. The enzymes were inhibited by a gamma-glutamyltranspeptidase inhibitor, L-serine plus borate.

Ascomycota↗
PubMed1986

[A study of the effect of (2"R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic, on reproduction. II. Its teratogenicity in rats and rabbits].

This paper describes the embryotoxicity and teratogenic effects of (2"R)-4'-O-Tetrahydropyranyladriamycin (THP). The drug was administered intravenously to female rats at 0.01, 0.03, 0.1 or 0.3 mg/kg daily from day 7 to day 17 of pregnancy and to female rabbits at 0.01, 0.05 or 0.1 mg/kg daily from day 6 to day 18 of pregnancy. Results were summarized as follows. Rats THP, at the highest dose of 0.3 mg/kg, decreased body weight gains of pregnant females. This dose caused a decrease in body weights of fetuses, tendencies to increase the rate of death of fetuses or of resorption, an increase in the number of lumbar vertebrae and a delayed ossification of forelimbs of fetuses. Other parameters were not affected by THP at any dose levels. At any dose levels, THP did not produce external, visceral or skeletal malformations in the offspring (F1), nor did it affect the development, physiological functions, behavior, mating, fertility or pregnancy of the offspring. However, at the highest dose level, THP decreased the weight of testes of the offspring. The results suggest that the maximum "no effect" dose level of THP to pregnant females and offspring is 0.1 mg/kg/day intravenously. Rabbits The highest dose of THP, 0.1 mg/kg, decreased the consumption of food and water by pregnant females, but at any dose levels, it did not affect their body weight gain. THP did not cause teratological effects such as external malformation or visceral and skeletal anomalies in the fetuses at any dose levels tested. The results suggest that the maximum "no effect" dose of THP is 0.05 mg/kg/day intravenously to pregnant females and above 0.1 mg/kg/day intravenously to fetuses.

Abnormalities, Drug-Induced↗
PubMed1985

Synthesis and antitumor activity of spergualin analogues. I. Chemical modification of 7-guanidino-3-hydroxyacyl moiety.

Many analogues and derivatives of an antitumor antibiotic, spergualin, were synthesized, and the relationships between the structure and the activity against mouse L-1210 tumor were studied. Both modification of the 15-hydroxyl group and alteration of chain-length of the omega-guanidinoacyl moiety affected the activity. 15-Deoxyspergualin (18, 1-amino-19-guanidino-11-hydroxy-4,9,12-triazanonadecane-10,13-d ion e) and its analogue 25 (1-amino-21-guanidino-11-hydroxy-4,9,12-triazauneicosane-10,13-dio ne) had strong activity, superior to that of spergualin.

Animals↗
PubMed1984

Stereochemistry of ornithine decarboxylase reaction.

To determine the steric course of the reaction of bacterial ornithine decarboxylase [EC 4.1.1.17], we have carried out the decarboxylation of L-ornithine in 2H2O and that of DL-[2-2H]ornithine in H2O, and obtained putrescine bearing a single deuterium atom in the C-1 position. The stereochemistry of [1-2H]putrescine was established by conversion to 1-(2-pyrrolidinyl)-2-propanone with acetoacetate and the pro-S hydrogen-specific diamine oxidase from pea seedlings. Analysis of deuterium content by gas chromatography-mass spectrometry showed that the deuterium label was fully retained during the conversion of [1-2H]putrescine produced by the decarboxylation of L-ornithine in 2H2O to 1-(2-pyrrolidinyl)-2-propanone, in contrast with the considerable loss of label from [1-2H]putrescine which was produced by the decarboxylation of DL-[2-2H]ornithine in H2O. The extent of loss of the deuterium label was in good agreement with the estimated value based on the isotope effect in the diamine oxidase reaction. These results indicate that the introduced deuterium (or hydrogen) is in the pro-R position at C-1 of putrescine, and consequently the ornithine decarboxylase reaction proceeds with retention of configuration.

Chemical Phenomena↗
PubMed1984

Toxicological studies on a new macrolide antibiotic, midecamycin acetate (miocamycin). Part VI-1. Acute toxicity in infant mice in comparison with young adult mice.

Sutherland and Weiss et al. reported cases of newborn human deaths or Gray syndrome after overdosage of chloramphenicol. In general, it has been reported that the acute toxicities of drugs are enhanced in immature animals compared with adult animals. The objective of this study was to determine the LD50 values in infant (5-day-old) and young adult (5-week-old) male and female mice after single subcutaneous and oral administration of MOM, non-crystalline solid and to estimate the toxicity ratio of those LD50 values. LD50 values of MOM, non-crystalline solid, were more than 5,000 mg/kg and the lethal toxicity was the same in infant and adult mice. Toxicity ratios were not obtained.

Age Factors↗
PubMed1984

Toxicological studies on a new macrolide antibiotic, midecamycin acetate (miocamycin). Part VI-2. Acute toxicity in infant rats in comparison with young adult rats.

In the present acute toxicity studies on MOM, non-crystalline solid, with infant male and female rats (5-day-old) and young adult male and female rats (5-week-old), it is confirmed as follows: LD50 values were estimated more than 5,000 mg/kg in both cases of subcutaneous and oral administrations. MOM, non-crystalline solid, did not exhibit any toxic effects similarly as previously reported with infant male and female mice and young adult male and female mice. There might be no definite age difference in toxicity between young and adult rats as LD50 values were estimated more than 5,000 mg/kg in independence upon the age. There might be no definite species difference in toxicity between mice and rats.

Age Factors↗