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Biomedical subjects

T Nara

Publications and source records attributed to T Nara.

At least 109 records · Page 6Linked to original sources
PubMed1988

Development of the human motor trigeminal nucleus.

The morphometric features of the motor trigeminal nucleus of the developing human brain were examined using complete serial celloidin sections of 13 brains, including 10 fetal brains. Our results suggest that the developmental processes of the motor trigeminal nucleus should be divided into four stages as follows: (1) primary stage, characterized by the early neuronal differentiation; (2) secondary or preparatory stage; (3) tertiary stage, characterized by massive neuronal death, and (4) postnatal stage, characterized by the maturation of neuropils. There were differences between the neuronal death observed in human and animal brains. Possible implications of these observations for the development of the nervous system are discussed.

Adolescent↗
PubMed1985

Histamine and 5-hydroxytryptamine in human scar tissue.

Patients with unstable scars in some areas of the body complain of local itchiness and pain, which may be caused by histamine and serotonin. Therefore, I measured these substances in scar tissue in various conditions taken at the time of operation. The histamine value was determined by the amount of carbon dioxide produced in histidine decarboxylase activity (HDCA); the measurement of 5-hydroxytryptamine (5-HT) was done by the Ninhydrin method. High values of HDCA were usually found in skin flaps and scar tissue around pressure sores. 5-HT activity reached a higher level in unstable scars than in stable scars.

Adolescent↗
PubMed1984

Breast feeding and neonatal behavioral state.

18 normal newborn infants were studied at the age of 5-6 days. Each infant was given breast or bottlefeeding in 2 different sessions on the same day. The newborn assessment was also done in these 2 3-hour sessions, in which sucking and behavioral state were determined. 10 of 18 infants were found to fall asleep soon after the breastfeeding, and to have more quiet sleep and less waking than after bottlefeeding. All of the mothers showed good breast-milk secretion when examined. The other 8 infants, who were not given enough milk, did not show the abovementioned tendency. These results suggest that breastfeeding exerts good influences on neonatal behavior.

Adolescent↗
PubMed1983

[Effect of intravenous administration of micronomicin on the inner ear of guinea pigs].

The present experiment was made to clarify the effect of intravenous administration of micronomicin (sagamicin, MCR) on the inner ear of guinea pigs (300--350 g). MCR was given to the animals intravenously at dose of 25, 50 mg/kg and 100 mg/kg, respectively for 28 days. Pinna reflex test in frequency range from 20 kHz to 0.5 kHz was performed before, during and after the administration. The temporal bones were removed after intravital perfusion of the inner ears with neutral formation after the end of the administration. Histopathological examination was performed on the serial celloidin sections of the inner ears which had been stained with hematoxylin eosin. The following results were obtained. 1. MCR had a mild corti toxicity, which did not show remarkable dose dependent increase. 2. MCR had more affinity for the vestibular organs than for the organ of corti. The affinity for the vestibular organ increased with increase in dose. 3. MCR showed less increase in corti toxicity in intravenous administration than in intramuscular injection. However, the affinity of MCR for the vestibular organ showed little more increase in the intravenous administration than in the intramuscular injection.

Aminoglycosides↗
PubMed1981

Cell wall composition of Micromonospora olivoasterospora, Micromonospora sagamiensis, and related organisms.

Cell walls of 19 Micromonospora species were analyzed for their components. All the cell walls had xylose and arabinose, but the presence of glucose, galactose, mannose, or rhamnose depended on the strain. Amino acids present in the walls consisted of glycine, glutamic acid, diaminopimelic acid, and alanine, in a molar ratio of approximately 1:1:1:0.6--0.8. 3-Hydroxydiaminopimelic acid, together with meso-diaminopimelic acid, was found in many species and was isolated from Micromonospora olivoasterospora to compare the color constant in an amino acid analyzer with that of meso-diaminopimelic acid. The cell walls of Micromonospora sagamiensis and M. olivoasterospora contained only D-alanine and not L-alanine. All species tested except Micromonospora globosa contained glycolate in an almost equimolar ratio to diaminopimelic acid in their cell walls. Among 45 strains of 12 genera examined, Actinoplanes, Ampullariella, Amorphosporangium, and Dactylosporangium species had a significant amount of glycolate in the whole cells. Based on these results, the primary structure of the peptidoglycan of Micromonospora is discussed.

Actinomycetales↗
PubMed1979

Fortimicins C, D and KE, new aminoglycoside antibiotics.

From the fermentation broth of Micromonospora olivoasterospora CS-26 that produced fortimicins A and B three new aminoglycoside antibiotics, fortimicins C, D and KE, were isolated. Fortimicins C and D exhibited potent, broad spectrum antibacterial activities against Gram-positive and negative bacteria, while fortimicin KE was only weakly active.

Aminoglycosides↗
PubMed1977

Fortimicin A production by Micromonospora olivoasterospora in a chemically defined medium.

A chemically defined medium was devised in order to study the requirements for fortimicin A production by Micromonospora olivoasterospora KY 11515. Soluble starch was the best carbon source; NH4Cl and NH4NO3 were suitable nitrogen sources both for the growth and fortimicin production. Amino acids such as L-asparagine, L-aspartic acid and L-glutamic acid showed some stimulatory effects on both growth and antibiotic production of M. olivoasterospora while L-serine stimulated only antibiotic production and L-citrulline only the growth. K2HPO4, MgSO4.7H2O and CaCO3 were essential especially for the antibiotic production. The most important finding was that vitamin B12, cobalt and nickel showed marked stimulatory effects on fortimicin A production.

Amino Acids↗
PubMed1977

A new aminoglycoside antibiotic complex--the seldomycins. I. Taxonomy, fermentation and antibacterial properties.

A soil isolate named Streptomyces hofunensis sp. nov. was found to produce seldomycin factors 1, 2, 3 and 5, new aminoglycoside antibiotics. Taxonomy of the producing organism, a study of cultural conditions for seldomycin production, and antibacterial activity of seldomycins are reported. Seldomycin factor 5 was the most active both in vitro and in vivo against gram-positive and negative bacteria.

Aminoglycosides↗