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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 667 records · Page 37Linked to original sources

Receptive field arrangement of color-opponent bipolar and amacrine cells in the carp retina.

Seven color-opponent bipolar and 50 color-opponent amacrine cells were identified in the carp retina and their spectral responses examined by using procion-dye-filled micropipets for staining and recording. Four of the bipolar cells had a +R-G-and three a +Y-B-type chromatic center. Six of the bipolar cells showed hyperpolarizing non-color-opponent surrounds, while one +R-G-type cell had a +Y-RB-type surround. This cell showed the greatest complexity of all bipolar cells identified so far, and its spectral property strongly suggests the existence of an intimate relation between it and +Y-RB-type horizontal cells. Examination and classification of the 50 amacrine cells revealed that 17 belonged to the +R-G, 16 to the -R+G, 6 to the +Y-B, and 11 to the -Y + B type. Most of these cells showed non-color-opponent surrounds. Yet, the similarity of the chromatic arrangement of their centers with that of the ganglion cells shows that the four basic types of color channels are already in existence in the amacrine cells where they seem to originate.

Animals↗

Cerebral microembolization. I. Pathophysiological studies.

Unilateral embolization of the brain was performed in cats by intracarotid injection of 10.5 million carbonized microspheres (15 +/- 5 mu). Intracranial pressure increased from 6.1 +/- 1.5 to 14 +/- 2.3 mm Hg within two minutes and continued to rise more slowly to 24 +/- 18.3 mm Hg within four hours. Embolization caused a nonhomogenous distribution of microflow, but initially had no effect on global cerebral blood flow, nor on cortical oxygen tension. Yet, a functional suppression of cortical electrical and metabolic activity occurred. The ipsilateral EEG flattened irreversibly after 15 seconds; the contralateral EEG was transiently suppressed shortly thereafter. Arteriovenous difference of oxygen fell from 10.5 +/- 0.7 to 5.3 +/- 0.6 vol%, and the arteriovenous difference of glucose fell from 11.7 +/- 3.9 to 2.6 +/- 2.1 mg/100 ml as a consequence of reduced oxygen and glucose extraction. Subsequently, severe vasogenic brain edema, secondary ischemia, and severe functional suppression developed between two and four hours.

Animals↗

A radioimmunoassay of plasma unconjugated and conjugated estetrol.

A radioimmunoassay for the measurement of both unconjugated and conjugaged estetrol in plasma has been developed. The antiserum obtained after 6 months of immunization with 6-oxoestetrol-6-(O-carboxy-methyl)oxim-BSA was used at a final dilution of 1:90,000 and showed almost no cross reaction with other steroids except for estriol at 1.24%. Esterol-glucosiduronate was synthesized by incubating with adrenalectomized rat liver homogenate and uridine diphosphoglucuronic acid. Then, plasma estetrol-glucosiduronate was measured in the same manner for unconjugated estetrol after hydrolysis with beta-glucuronidase. Sephadex LH-20 column chromatography (7X110 mm, benzene:methanol, 85:15) was employed for accurate assessment. The sensitivity was 10 pg and the smallest amount measurable was 40 pg/sample. The method bland was consistently negligible. The intra and inter assay precision was 11.8% and 14.2% for unconjugated estetrol and that for estetrol-glucosiduronate was 13.5% and 17.1%.

Antibody Specificity↗

Termination of early pregnancy by ONO-802 (16,16-dimethyl-trans-delta2-PGE1 methyl ester).

ONO-802 was infused into the uterine cavity for the termination of early pregnancy in 45 healthy volunteers. Forty two (93%) of the 45 cases had complete abortions and two had incomplete abortions. Nine (20%) of the 45 volunteers complained of nausea, 7 (16%) vomited and 5 (11%) complained of abdominal pain. Neither diarrhea nor weakness was observed. These results suggest that ONO-802 is more acceptable for the termination of early pregnancy than is PGF2alpha.

Abortion, Induced↗

[Extracalvarial meningioma--report of a case (author's transl)].

A case of extracalvarial meningioma was reported. 75-year-old man was admitted to our department on November 11, 1974 because of a slowly growing tumor in the right frontoparietal area. The tumor was ovoid and 15x13 cm in size, protruding 5 cm above the skin level, and covered by the normal scalp. Neurological and electroencephalographic examination were negative. Spinal tap showed an opening pressure of 90 mm of water and clear CSF with 62 mg/dl of protein content. Plain roentgenogram and laminagram of the skull revealed both osteolytic and osteoblastic change in the outer and inner table of the skull just beneath the tumor. A right external carotid angiography disclosed a homogeneous extracalvarial tumor stain supplied by the superficial temporal artery and draining into the superficial temporal vein. A right carotid angiogram showed a 1 cm thick avacular area. The segmentally occluded superior sagittal sinus was displaced inward together with bridging collateral channels. Radiologically these picture corresponded to "intracranial non-globoid shape or avascular meningioma" discussed by Huckman et al. The tumor was well-circumscribed, encapsulated and loosely adherent to the periosteum and the skull except for a small portion through which the tumor was communicated with its intracranial part. Histological examination revealed that it was a typical endotheliomatous meningioma. This case should be allocated to the transitional or intermediate type between Lopez II and III type. In the schematical presentation (Fig. 6) we tried to readjust the rather confusing concept and classification of the extracalvarial meningioma.

Aged↗

Radioimmunoassay of 16alpha-hydroxy-dehydroepiandrosterone and its sulfate.

A simple and reliable radioimmunoassay for plasma 3beta, 16alpha-dihydroxy-5-androsten-17-one(16alpha-OH-DHEA) and its sulfate has been developed. The antiserum against 16alpha-OH-DHEA and its sulfate (16alpha-OH-DHEA-3-sulfate) was produced in rabbits immunized with 16alpha-OH-DHEA-3-succinate-bovine serum albumin. This antiserum reacted well with both 16alpha-OH-DHEA and its sulfate and only slightly cross reacted with DHEA and its sulfate. The coefficient of variation (C.V.) of the intra assay was 10.26% for 16alpha-OH-DHEA and 12.32% for 16alpha-OH-DHEA-S. The C.V. of the interassay were 14.34% for 16alpha-OH-DHEA and 15.64% for 16alpha-OH-DHEA-S. The umbilical artery concentrations for 16alpha-OH-DHEA and 16alpha-OH-DHEA-S were 7.20 +/- 6.71 ng/ml and 4490 +/- 2140 ng/ml, and the umbilical vein concentrations were 14.20 +/- 11.27 ng/ml and 2970 +/- 1450 ng/ml respectively.

Antibody Specificity↗