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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 595 records · Page 33Linked to original sources
PubMed1983

Lentoidogenesis from neural retina cells in culture is affected by interactive relationships between different cell types.

By centrifugation in a Percoll gradient, two cell fractions were separated from cell populations harvested from 8-day cultures of neutral retina cells of 3-5-day-old quail embryos. The heavy (H-) fraction contained mostly N-cells, which are considered to be putative neuronal cells, while the light (L-) fraction contained both E-cells, putative retinal glial cells, and N-cells. Determination of choline acetyltransferase activity in both fractions suggested that this enzyme is predominantly localised in N-cells. After replating the separated L-fraction for further culturing, frequent lentoidogenesis occurred from clusters of N-cells which, though few in number, were included in this fraction. Addition of H-fraction to L-fraction cells caused a significant increase in lentoidogenesis up to a ratio of N- to E-cells of 3:1. However, addition of excess H-fraction cells beyond this ratio inhibited lens differentiation. This difference in the expression of lens phenotypes resulting from the different ratios of H- and L-fraction was confirmed by monitoring the level of delta-crystallin in cultures. These results are discussed in the light of interactive relationships between N- and E-cells in the transdifferentiation of neural cells into lens in cell culture.

Animals↗
PubMed1983

[Autopsy case of extra-neural metastasis of suprasellar pineal germinoma].

A 19-year-old boy was admitted with a suprasellar tumor. On May, 1980 he underwent craniotomy and subtotal tumor removal. The pathological diagnosis was germinoma. In July, 1981, a solitary angiomatous tumor appeared in the left back skin and was resected. The pathological diagnosis was choriocarcinoma, thus, a final diagnosis of suprasellar choriocarcinoma was made. At the first admission, his LH was 100 miu/ml; FSH, 2.4 miu/ml, while; at the second admission, LH was 500 miu/ml; FSH, 9.9 miu/ml, HCG, 13000 miu/ml. Irradiation combined with chemotherapy brought no improvement of his symptoms and he died. At autopsy, multiple metastatic foci were recognized in the lungs, liver, kidney, intestine, skin and brain.

Adult↗
PubMed1983

Effect of local anaesthetics on human natural killer cell activity.

We explored the effects of local anaesthetics, which are proposed to affect the plasma membrane, on human natural killer (NK) cells. Human NK cell activity was inhibited by lidocaine and procaine in a dose-dependent manner. Procaine inhibited not only NK cytolysis but also the binding of NK cells to target cells when NK cells were pre-incubated with procaine, whereas procaine inhibited NK cytolysis without interfering with the binding when it was added after the binding was completed. These findings suggest that local anaesthetics may inhibit not only the recognition process but also the post-recognition process of human NK cells.

Adult↗
PubMed1982

Influence of cerebral venous obstruction on cerebral circulation in humans.

The influence of cerebral venous obstruction on cerebral circulation was investigated in three patients with cerebral venous and sinus thrombosis in the chronic stage. The xenon Xe 133 intracarotid injection method was used to evaluate the cerebral blood flow (CBF). Values for CBF showed a slight decrease in all patients, despite intact cerebrovascular autoregulation. In two of the three patients, hypercapnia failed to increase CBF, but hyperventilation decreased CBF normally. This phenomenon can be explained on the basis of both failure of the capacitance vessels on the venous side to dilate and an increased intracranial pressure and is not attributable to decreased carbon dioxide reactivity. Long-lasting obstruction of the venous system can lead to a slight reduction in CBF and not affect cerebral autoregulation or CO2 reactivity itself in humans.

Adolescent↗
PubMed1982

The abortifacient effect of 16,16-dimethyl-trans-delta 2-PGE1 methyl ester, a new prostaglandin analogue, on mid-trimester pregnancies and long-term follow-up observations.

The present clinical trials revealed that 16,16-Dimethyl-trans-delta 2-PGE1 methyl ester in the form of vaginal suppositories is highly effective in inducing mid-trimester termination of pregnancies. It also showed that prior treatment with laminaria and metreurynter may enhance the success rate while reducing the incidence and severity of side effects. It is easy and safe to use clinically, with minimal side effects, and in our series, revealed no deleterious effects on ensuing reproductive physiology. However, the definite mechanism involved in the action of this new analogue to cause myometrial contractions is still not completely understood, and requires further intensive investigation.

Abortion, Induced↗
PubMed1982

Abortifacient effect and uterine cervix-dilating action of 16, 16-dimethyl trans delta 2 PGE1 methyl ester (ONO 802) in the form of a vaginal suppository (a randomized, double-blind, controlled study in the second trimester of pregnancy).

A newly synthesized 16, 16-dimethyl trans delta 2 PGE1 methyl ester (ONO 802) was clinically applied in the form of a vaginal suppository for therapeutic abortion of second trimester pregnancies. Its effects were studied in a double-blind test comparing it with an inactive placebo suppository. The study was conducted at 12 Japanese university hospitals. The number of patients was 125 in total, i.e. 63 receiving ONO 802 vaginal suppository (containing 1.0 mg ONO 802) and 62 receiving inactive placebo suppository. ONO 802 was more effective than placebo with a success rate of 87% (complete (71%) and incomplete (16%) abortions). The onset of uterine contractions was observed in 154.3+/-18.1 min. and the onset of uterine bleeding in 323.6+/-41.0 min. The expulsion of the fetus and placenta was observed in 955.4+/-97.0 and 961.6+/-97.0 min., respectively. The cervix dilating effect of ONO 802 was observed in 63.5% of the patients at 3 hours after the start of administration. Nausea, vomiting, abdominal cramps, diarrhea and pyrexia were noticed. However, all these side effects were transient and mild, requiring no treatment. No abnormality was observed in the puerperal course, duration of uterine bleeding or onset of subsequent menstruation following the therapeutic abortion. Therefore, the present study demonstrated that ONO 802 vaginal suppository was an effective and valuable drug for therapeutic abortion of second trimester pregnancies.

Abortifacient Agents↗
PubMed1982

In vivo effect of methylcobalamin on the peripheral nerve structure in streptozotocin diabetic rats.

To study in vivo effect of methylcobalamin (CH3-B12) on the peripheral nerve structures, rats with experimental diabetes induced by streptozotocin were administered with daily intramuscular injection of CH3-B12 (500 microgram/kg) for 16 weeks. By isolated nerve fiber studies, CH3-B12-treated diabetic rats showed less incidence of paranodal demyelination as an early sign of segmental demyelination than non-treated diabetic rats. From morphometrical analysis on sural nerves, the reduction in the density of myelinated nerve fibers, nerve fiber size and axon size of myelinated fibers was definitely protected in treated diabetic rats. The results suggested that continuous treatment with CH3-B12 had an ameliorative effect on the peripheral nerve lesions in experimental diabetic neuropathy.

Animals↗
PubMed1982

Histocompatibility antigens in Parkinson's disease.

The possible association of 7 HLA specificities in the HLA-A locus and 16 specificities in the HLA-B locus with susceptibility to Parkinsonian syndrome was investigated in a total of 36 patients with paralysis agitans (PA), as well as in 11 patients with other Parkinsonian syndromes, and 176 controls in Japan. There was no clear association between HLA-A or -B locus antigens and PA or other Parkinsonian syndromes. Patients with PA were subdivided according to sex, age of onset, clinical manifestations, and response to L-Dopa therapy. There was, however, no apparent association between HLA-A or -B locus antigens and any of the variables investigated. Our data do not provide any evidence for genetic susceptibility in the pathogenesis of PA.

Adult↗