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Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 1,027 records · Page 57Linked to original sources
PubMed1981

Sensitivity to GABA of neurons of the dorsal and ventral lateral geniculate nuclei in the rat.

GABA was applied iontophoretically to dorsal and ventral lateral geniculate (LGd and LGv) neurons in rats. Spontaneous discharges were readily suppressed in both species of neurons. While in LGd neurons, evoked discharges by optic nerve stimulation were suppressed as readily as were spontaneous discharges, LGv neurons were characterized in that evoked discharges were much more resistant than spontaneous discharges.

Animals↗
PubMed1981

Properties of ipsilateral retinogeniculate afferents in albino and hooded rats.

By recording single unit activities from the dorsal lateral geniculate nucleus in albino and hooded rats, physiological properties of the ipsilateral retinogeniculate afferents were compared with those of the contralateral ones. The results show that the ipsilateral retinogeniculate pathway was characterized by intermediate conduction velocities, relatively high incidence of the tonic response and the visual field representation of central 30 degrees from the vertical midline on both sides.

Afferent Pathways↗
PubMed1981

Treatment of biliary atresia: a study of our operative results.

The operative results in 87 biliary atresia cases were investigated from the aspect of the histologic findings in the liver and the remnant of the extrahepatic bile ducts, and the details of the operative procedures. The degree of liver fibrosis, the liver cell changes, and the type of extrahepatic bile ducts are closely related to our operative results. Our operative results have been improving since 1977 due to the advancement of microsurgical techniques and a new type of operative procedure for prevention of ascending cholangitis. Twenty-five of 29 cases (86.2%) surgically corrected are alive, showing bile excretion, and are in a satisfactory general condition.

Bile Ducts↗
PubMed1981

A Kr-81m inhalation method for detection of absence of uniform ventilation in asthma.

In an attempt to compare inhalation methods in detecting abnormal patterns of ventilation, the following four techniques were applied in 12 asthmatic patients: spontaneous respiration with a Kr-81m gas-air mixture (SP technique); serial inhalation of a Kr-81m gas-air mixture from the level of residual volume to total lung capacity (VC technique); bolus inhalation of 10 ml or Kr-81m gas from the level of residual volume, followed by air, to total lung capacity (RV technique); bolus inhalation of 10 ml of Kr-81m gas from the level of functional residual capacity, followed by air, to total lung capacity (FRC technique). Before exercise, abnormalities were detected by the RV and FRC techniques, but no abnormalities were detected by SP and VC techniques. On studies done after exercise, the abnormalities were detected by all the described techniques. However, they were best demonstrated by the RV technique and shown least well by the VC method.

Adolescent↗
PubMed1981

Monozygotic twins discordant for rubinstein-taybi syndrome.

A pair of male monozygotic twins discordant for Rubinstein-Taybi syndrome is reported. Monozygosity of the twins was established using blood grouping, typing of serum proteins, isozymes, HLA, and chromosomal heteromorphisms. The twins are the first twin pair discordant for the syndrome in which monozygosity has been firmly established. The pathogenesis of the syndrome is discussed in relation to the occurrence of both discordant and concordant monozygotic twins.

Abnormalities, Multiple↗
PubMed1981

Effect of dopamine on regional pulmonary perfusion.

Dopamine effect on regional pulmonary perfusion in the right upper lobe was studied in 6 dogs in which the lobe was isolated by a balloon catheter and artificially ventilated with nitrogen, air or 60% oxygen in nitrogen, while the rest of the lungs was allowed spontaneous air respiration. Dopamine was administered at the rate of 20 micrograms/kg/min. Each dog served as its own control. There was no change in the regional vascular responses to the different alveolar oxygen tensions in the right upper lobe before and after dopamine administration.

Animals↗
PubMed1981

[Genetic studies of hydatidiform mole with 46,XY karyotype (author's transl)].

Complete hydatidiform moles are androgenetic in origin. The majority of them show a 46,XX karyotype, while some are 46,XY. Chromosome analysis of 75 complete moles revealed three (4.0%) to be so. The XY moles, the patients and their husbands were studied for various polymorphic markers, including chromosomal Q-banding heteromorphism, HLA antigen, phosphoglucomutase-1 and esterase D, in order to determine the origin of XY moles. In all of the three XY moles studied, some of the polymorphic markers were not inherited from the patients, but they were exclusively paternal. Thus, these moles were androgenetic in origin. They also showed both homozygous and heterozygous Q-banding patterns in their homozygous chromosome pairs. Therefore, they were of dispermic origin. In conclusion, XY moles are of dispermic origin.

Adult↗
PubMed1980

GABA sensitivity of neurons of the visual layer in the rat superior colliculus.

Inhibitory action of iontophoretically applied GABA was examined on neurons in the visual layer of the rat superior colliculus (SC). Spontaneous discharges of all neurons tested were readily abolished by GABA ejected with currents less than 25 nA. In some cells the discharges evoked by near threshold electrical stimulation of the optic nerve or those evoked by a spot of light moving across receptive fields were suppressed by the same dose of GABA as that required to abolish the spontaneous discharge. However, in other cells the evoked discharges were much more resistant to GABA than the spontaneous activity. GABA sensitivity of the evoked activities was examined on various classes of SC cells which were identified by their recording depth, response latency to electrical stimulation of the optic chiasm and other properties. SC cells of the visual layer were classified into 8 types: classes Ia and Ib in the most superficial layer (N3 zone), class II in the thin layer below the N3 (N2 zone) and classes IIIa, IIIb, IVb and IVc in the deepest layer below the N2 (N1 zone). Effects of GABA upon these cell classes are summarized as follows; (1) Ia and IVb cells were readily suppressed by GABA, (2) Ib and II and most of IIIa and IVc cells were GABA-insensitive, and (3) GABA sensitivity varied from cell to cell in classes IIIb and IVa.

Animals↗
PubMed1980

H+-sensitivity and pattern of discharge of neurons in the chemosensitive areas of the ventral medulla oblongata of rats in vitro.

Effect of H+ on neuronal activity in medullary chemosensitive structures was analyzed in brain slices of the rat in vitro. Spontaneous discharges of spikes were recorded from two populations of neurons in the ventral surface layer of the medulla oblongata. Neurons located in the rostro-lateral part of the hypoglossal nerve root (area II) fired irregular phasic and/or continuous tonic discharges. More rostral and medial to it, a population of 'H+-sensitive' tonic neurons was found previously (area I). The phasic activity of neurons in area II with variable bursting and silent periods (0.1--120 s) was either increased or decreased by H+. Some neurons firing tonically in area II started to show phasic burst under low pH conditions. After cutting the slice between area I and II, the number of neurons firing phasically in area II was reduced, and the activity of area II neurons was mostly depressed by H+. An increase in activity of area I neurons by H+ was kept intact even after section. The results suggest that neurons in area I play an important role not only in the excitatory response to H+ of area II neurons but also in the initiation of phasic neuronal discharges in area II.

Animals↗