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Biomedical subjects

M Fujimoto

Publications and source records attributed to M Fujimoto.

At least 523 records · Page 29Linked to original sources
PubMed1982

[Estrogen receptors in meningiomas and neurinomas (author's transl)].

In the brain tumors hormone dependency has long been suggested from the evidence that meningiomas and neurinomas are frequently seen in female and that they enlarge during pregnancy presumably as a result of hormonal change. Recently the presence of estrogen receptor (ER) in meningiomas, neurinomas and pituitary adenomas were documented in some preliminary reports. In this report we estimated the ER in the tissue of 15 patients with meningiomas (13 females and 2 males) and 5 with neurinomas (2 females and 3, males). The estrogen receptor level was determined by Scatchard analysis. The results were obtained as follows: In meningiomas, 80% (4/5) of premenopausal females, 25% (2/8) of postmenopausal females and 0% (0/2) of males had receptor activity. Maximal binding sites (Bm; fmol/mg cytosol protein) and dissociation constant (Kd; x 10(-10)M) are as follows: Bm=20.8+/-12.2 (premenopause; n=4) or 22.8 (postmenopause; n=2) and Kd=2.8+/-0.7 (premenopause) or 6.9 (postmenopause). In neurinoma, 33% (1/3) of males and 0% (0/2) of females had receptor activity. Bm and Kd are as follows: Bm=25.0 and Kd=2.3. The ER detectable rate in meningiomas was much higher in premenopausal females. There was a suggestion that some brain tumors are responsible to estrogen via cellular estrogen receptor.

Adult↗
PubMed1981

Field potential induced by injection of potassium ion into the frog retina: a test of current interpretations of the electroretinographic (ERG) b-wave.

Using excised frog retinas, the field potential induced by mechanical intraretinal injection of K+ Reinger's was mapped by a penetrating electrode. The high K+ Ringer's contained 75 mM K+ and the amount per injection was of a sphere about 40-50 micron in diameter. The K+ injection pipette was so made that it also served for recording potentials at the site of K+ injection. The study revealed that: (1) a maximum negativity is produced at the depth of K+ injection; and that (2) the negativity subsides in both directions, proximally and distally; but that (3) when recording from the retinal surfaces, the vitreal side becomes positive relative to the receptor side, irrespective of the retinal depth of K+ injection, excepting for the innermost layer of some 20 micron in thickness where some uncertainty remains. The results indicated that the "neutral zone", as defined as a zone where a high K+ produces no potential differences between the opposite retinal surfaces, is localized very close to the inner limiting membrane. Recent interpretations of the b-wave on the Müller cell hypothesis are discussed on the basis of our results.

Action Potentials↗
PubMed1981

Correlative ontogenetic development of catecholamine- and LHRH-containing nerve endings in the median eminence of the rat.

The ontogenetic development of catecholamine (CA)- and LHRH-containing nerve endings in the median eminence of the rat was investigated by combining fluorescence histochemistry and immunohistochemistry in the same tissue section. LHRH-terminals appeared earlier than CA-terminals and were already detectable in the lateral part of the external layer of the central ME on the first day after birth. CA-nerve endings were first seen in a corresponding region of the ME on the seventh postnatal day. At this stage both types of terminals showed the earliest manifestation of a correlative pattern of their distribution. Subsequently the development of both types of nerve endings proceeded rapidly, and at 14 days their distribution pattern corresponded to that in adult animals. The authors conclude that at this stage the CA-neurons play a constant and significant role in the release of LHRH into the portal capillaries. The correlation between both types of nerve endings and the ontogenetic development of the capillary plexuses of the hypophysial portal system is discussed.

Age Factors↗