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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 829 records · Page 46Linked to original sources
PubMed1987

Cytogenic analysis of dominant lethal effects of mitomycin C and ethyl methanesulfonate.

To gain further insight into the mechanism of induction of dominant lethal mutations, the relationship between chromosome aberrations in bone marrow and in male germ cells after treatment with mitomycin C (MMC) and ethyl methanesulfonate (EMS) was examined. In addition, we obtained fertilized eggs from the oviducts of crossbred female mice in the same way as in the dominant lethal mutation test, and examined chromosome aberrations in male pronuclei. MMC 2.5 and 5.0 mg/kg, EMS 175 and 350 mg/kg were given subcutaneously to slc-ICR mice. It was concluded that MMC causes a decrease in the sperm count by killing germ cells, which in turn causes an increase in the number of unfertilized eggs and preimplantation egg loss. MMC seems also to cause invisible damages in the chromosomes of spermatocytes which lead to dominant lethality. EMS induced chromosome damage in the post-meiotic germ cells, and this damage, in turn, produced chromosome aberrations in the eggs, resulting in a high incidence of dominant lethality.

Animals↗
PubMed1987

Antigenic and restriction endonuclease analyses of new adenovirus types 19 and 37 causing acute conjunctivitis.

DNA restriction endonuclease cleavage analysis and serum neutralization test were performed in strains of adenovirus types 19 (Ad-19) and 37 (Ad-37) isolated from patients with acute conjunctivitis in Sapporo (Japan), Kaohsiung (Taiwan) and Pusan (South Korea) during the period of 1977 to 1984. Ad-19 and Ad-37 could be roughly differentiated, but a fair degree of cross reactivity was noted by serological test. By DNA restriction endonuclease analysis, Ad-19 isolates, Ad-19 prototype strain and Ad-37 strains were clearly differentiated. It was suggested by DNA cleavage patterns that both Ad-19 and Ad-37 isolates in East Asia are the same as those currently found in Europe and the USA. A new subtype of Ad-37 was found by DNA cleavage analysis among the isolates obtained in Sapporo and Kaohsiung in 1980.

Acute Disease↗
PubMed1987

The ancestor of the adaptive immune system was the CAM system for organogenesis.

The adaptive immune system as we understand it is uniquely possessed by vertebrate species and by none other. Nevertheless, it is generally thought that this system represents the ultimate sophistication of much older cell-cell interaction mechanisms. In this paper, I have suggested that plasma membrane cell adhesion proteins that were involved in ontogenic organogenesis since time immemorial were the ultimate ancestor of the adaptive immune system. N-CAM of the chicken for neuronal organogenesis already possesses four beta 2-microglobulin-like domains and it is this domain from which the adaptive immune system sprang. The germ for this beta 2-microglobulin-like domain is already found in the cell adhesion protein of the slime mold straddling the border between unicellular and multicellular eukaryotes. A slightly different version of the above view has recently been expressed by my colleagues.

Amino Acid Sequence↗
PubMed1986

Complete amino acid sequence of the large subunit of the low-Ca2+-requiring form of human Ca2+-activated neutral protease (muCANP) deduced from its cDNA sequence.

The complete amino acid sequence of the large subunit (catalytic subunit) of human low-Ca2+-requiring-calcium-activated neutral protease (muCANP) was deduced from its cDNA base sequence. It is composed of 714 amino acid residues and its sequence is highly homologous to the chicken CANP sequence determined previously. Human muCANP, like chicken CANP, has a clear 4-domain structure, and their fundamental structures are essentially the same, although their Ca2+ sensitivities are significantly different. The role of each domain in the Ca2+ sensitivity and protease activity of CANP is discussed on the basis of sequence comparison.

Amino Acid Sequence↗
PubMed1986

Nucleotide sequence of chick 14K beta-galactoside-binding lectin mRNA.

cDNA for chick 14K beta-galactoside-binding lectin mRNA was cloned and the nucleotide sequence determined. The deduced amino acid sequence and the results of in vitro translation of its mRNA suggest that this lectin does not include any cleavable signal sequence while it exists in extracellular matrix. Comparison of the primary structures has shown that chick 14K lectin includes some regions homologous to those in discoidin I, which is also known to be located in extracellular matrix and lack signal peptide. The results imply some relation between these two lectins in spite of their great phylogenetic separation.

Amino Acid Sequence↗
PubMed1986

Gene structure of calcium-dependent protease retains the ancestral organization of the calcium-binding protein gene.

The gene structure of calcium-dependent protease (Ca2+-protease) was determined. It comprises at least 21 exons, and these were assigned to the 4 functional domains of the protease. The protease domain does not show clear correlation between exons and functional units, but the calmodulin-like calcium-binding domain shows strong correlation. Each of the 4 consecutive calcium-binding regions in the C-terminal part of Ca2+-protease is encoded by one exon. This gene structure supports the idea that the 4 calcium-binding regions of calcium-binding proteins such as calmodulin arose by 2 steps of gene duplication.

Animals↗
PubMed1986

The all pervasive principle of repetitious recurrence governs not only coding sequence construction but also human endeavor in musical composition.

Organisms which have evolved on this earth are governed by multitudes of periodicities; tomorrow is another today, and the next year is going to be much like this year. Accordingly, the principle of repetitious recurrence pervades every aspect of life on this earth. Thus, individual genes in the genome have been duplicated and triplicated often to the point of redundancy, and each coding sequence consists of numerous variously truncated as well as variously base-substituted copies of the original primordial building block base oligomers and their allies. This principle even appears to govern the manifestations of human intellect; musical compositions also rely on this principle of repetitious recurrence. Accordingly, coding base sequences can be transformed into musical scores using one set rule. Conversely, musical scores can be transcribed to coding base sequences of long open reading frames.

Animals↗
PubMed1986

Chronic manganese poisoning: a neuropathological study with determination of manganese distribution in the brain.

An autopsy case of a 52-year-old man suffering from chronic manganese poisoning (CMP) is reported with determination of the manganese distribution in the brain. The patient had been working in a manganese ore crushing plant since 1965. In 1967 he began to complain of difficulties in walking and diminished libido. Later, he developed various neuropsychiatric symptoms including euphoria, emotional incontinence, masked face, monotonous speech, "cock-walk", increased muscle tone, weakness of upper and lower extremities, tremor of the eye lids, and exaggeration of knee jerks. The major neuropathological change was degeneration of the basal ganglia, in which the pallidum was severely affected. The pallidum disclosed a loss and degeneration of nerve cells, which was especially marked in the medial segment, a prominent decrease of myelinated fibers, and moderate astrocytic proliferation. The substantia nigra was intact. Distribution of manganese in the brain of the present case of CMP was determined using flameless atomic absorption spectrometry and compared with control cases and also a case of Parkinson's disease (PD). There was no significant difference between the control cases and the case of PD in average concentration of manganese and its distribution in the brain. The present case of CMP showed no elevation in average concentration of manganese in the brain. However, there were some changes in its distribution. Thus, the continuance of neurological disorders in CMP is not linked to an elevated manganese concentration itself in the brain. CMP appears to be different from PD in neuropathology and manganese behavior in brain.

Aged↗
PubMed1986

Subretinal neovascularisation and snow banking in a case of sarcoidosis: case report.

A 49-year-old Japanese man presented with chronic granulomatous uveitis in his left eye. Later he developed macular subretinal neovascularisation. The chest x-ray showed bilateral hilar lymphadenopathy. Bronchoscopy and gallium-67 scanning were positive, PPD skin test negative, and serum angiotensin converting enzyme (ACE) levels increased. Ophthalmoscopy and fluorescein angiography of the left eye showed perivasculitis, retinochoroidal exudates, snow banking, and vitreous opacity. On these findings, the diagnosis of sarcoidosis was made. Treatment was based on topical corticosteroids, mydriatics, beta blockers, and oral carbonic anhydrase inhibitors. After 15 months the visual acuity decreased in the left eye, and a neovascular membrane was observed in the macula. Fluorescein angiography confirmed subretinal neovascularisation. Almost two years later the patient still has the neovascular membrane in his left eye.

Eye Diseases↗
PubMed1986

In vitro fertilization and development of ova obtained from female mice treated with aminopterin and mitomycin C.

We examined the effects of mitomycin C and aminopterin on ovulation in vivo and, fertilization, subsequent cleavage and implantation in slc-ICR female mice using methods of fertilization and culture in vitro. Chemicals were injected into mice at the MI (meiosis I) stage or 3 hours before the MI stage in order to examine their toxicity. Mitomycin C did not affect ovulation, but decreased the rate of fertilization. A high dose of mitomycin C (4 mg/kg) inhibited fertilization and the development of ova to the 2-cell stage. Aminopterin affected neither ovulation nor fertilization. At either the MII (meiosis II) stage or 3 hours before the MII stage, high doses (4 and 2 mg/kg) of mitomycin C arrested cleavage and implantation. The cleavage was blocked frequently between the 3-4 cell stage and the 5-8 cell stage. Aminopterin affected neither cleavage nor implantation.

Aminopterin↗
PubMed1986

Structure and function of the small (30K) subunit of calcium-activated neutral protease (CANP).

Calcium-activated neutral protease (CANP), a typical intracellular protease, is composed of a catalytic 80K subunit (80K) and a 30K subunit (30K) of unknown function. The structure of rabbit CANP 30K was examined to clarify its role in the enzyme function. It has a clear two-domain structure composed of 266 amino acid residues. The N-terminal domain presumably determines the location of CANP, whereas the C-terminal domain is a calmodulin-like Ca2+-binding domain and regulates CANP activity.

Amino Acid Sequence↗