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Biomedical subjects

Y Fukuda

Publications and source records attributed to Y Fukuda.

At least 865 records · Page 48Linked to original sources
PubMed1986

Ipsilateral retinal projections and laminations of the dorsal lateral geniculate nucleus in the eastern chipmunk (Tamias sibiricus asiaticus).

The ipsilateral retinal projections and laminations of the dorsal geniculate nucleus (LGNd) were studied in the eastern chipmunk (Tamias sibiricus asiaticus). From cyto-, myelo- and chemoarchitectures the LGNd was divided into the ventromedial and dorsolateral parts. Anterograde axonal transport of wheat germ agglutinated horseradish peroxidase (WGA-HRP) and Fink-Heimer staining after unilateral eye removal both indicated that the ipsilateral projection terminates in lamina 2 of the ventromedial part and in lamina 3b of the dorsalateral part. The remaining laminas, lamina 1 of the ventromedial part and laminas 3a and 3c of the dorsolateral part, receive afferents from the contralateral retina. It was suggested that laminas 1 and 2 of the chipmunk's LGNd correspond to laminas A and A1 of the cat's LGNd, and the lamina 3 complex to its lamina C complex.

Animals↗
PubMed1986

Metabolism of 2-oxoaldehydes in yeasts. Possible role of glycolytic bypath as a detoxification system in L-threonine catabolism by Saccharomyces cerevisiae.

L-Threonine catabolism by Saccharomyces cerevisiae was studied to determine the role of glycolytic bypath as a detoxyfication system of 2-oxoaldehyde (methylglyoxal) formed from L-threonine catabolism. During the growth on L-threonine as a sole source of nitrogen, a large amount of aminoacetone was accumulated in the culture. The enzymatic analyses indicated that L-threonine was converted into either acetaldehyde and glycine by threonine aldolase or 2-aminoacetoacetate by NAD-dependent threonine dehydrogenase. Glycine formed was condensed with acetyl-CoA by aminoacetone synthase to form 2-aminoacetoacetate, a labile compound spontaneously decarboxylated into aminoacetone. The enzyme activities of the glycolytic bypath of the cells grown on L-threonine were considerably higher than those of the cells grown on ammonium sulfate as a nitrogen source. The result indicated the possible role of glycolytic bypath as a detoxification system of methylglyoxal formed from L-threonine catabolism.

Acetyl Coenzyme A↗
PubMed1986

Two-site enzyme immunoassay for alpha-fetoprotein involving column chromatography.

We developed a sensitive enzyme immunoassay for alpha-fetoprotein by use of a novel separation method. The assay system consisted of goat antibodies labeled with beta-D-galactosidase, the same antibodies labeled with F(ab')2 fragments of rabbit IgG, and a microcolumn (0.1 ml) containing Sepharose 4B with immobilized goat antibodies to rabbit IgG. Each serum sample or standard alpha-fetoprotein was incubated with the enzyme-labeled antibodies and the F(ab')2-labeled antibodies, then the reaction mixture was passed through the column. alpha-Fetoprotein, which linked with both the enzyme-labeled antibody and the F(ab')2-labeled antibody, bound to the antibody to rabbit IgG immobilized on Sepharose 4B in the column. The column was washed to remove the unbound label, and the buffer in the column was replaced by a solution of omicron-nitrophenyl-beta-D-galactoside. After 60 min at 30 degrees C, the enzyme reaction was stopped by washing the column with sodium carbonate solution. From the absorbance of the eluate at 420 nm, alpha-fetoprotein in the sample could be determined. Values obtained by this method and those obtained by a radioimmunoassay correlated well (slope = 0.989, y-intercept = -0.327 micrograms/l, r = 0.995).

Animals↗
PubMed1986

Hepatic vascular endothelial cells heterogenously express surface antigens associated with monocytes, macrophages and T lymphocytes.

During studies of the antigenic and functional properties of hepatic sinusoidal lining cells in situ, we found that only the sinusoidal endothelial cells share antigens with a peripheral blood macrophage subset capable of presenting soluble antigens and triggering autologous mixed lymphocyte reactions. They were HLA-DR+, OKM1-, OKM5+. Vascular endothelial cells in the portal areas and central veins were HLA-DR+, OKM1- and OKM5-. The sinusoidal endothelial cells also expressed an antigen found on helper/inducer (OKT4 and Leu3 a) T lymphocytes. Thus, the present study suggests that endothelial cells in different anatomic compartments in the liver heterogenously express surface antigens associated with monocytes, macrophages and T lymphocytes and possess distinct immunological functions.

Antibodies, Monoclonal↗
PubMed1986

Malignant schwannoma of the mandible.

A case of malignant schwannoma occurring in the mandible of a 76-year-old Japanese woman is presented. Results of the gross examination are described as well as the surgical procedure. Details of the staining techniques for examination of the biopsy specimen are given. The histopathological findings are mentioned including those obtained from radiographic, microscopic, and electron microscopic examination. A discussion of the disease and of its difficulty of diagnosis follows.

Aged↗
PubMed1986

A light and electron microscopic study of the regenerative epithelium in the intrahepatic bile duct. Experimental study of local direct instillation of paraquat into the intrahepatic bile ducts of rats.

To date, no reliable report on the regeneration of the intrahepatic bile duct epithelium following damage to the duct has been published. In this study, a direct instillation of paraquat dichloride into the intrahepatic bile ducts of rats was carried out, and the livers were examined under light and electron microscopy. One hour after treatment, the biliary epithelia showed degeneration and necrosis, and these changes remained for a considerable period in a large majority of the ducts examined. Three weeks after instillation, low columnar epithelium consisting of hyperchromatic nuclei and eosinophilic cytoplasm was present in a medium-sized bile duct, which was collared by marked periductal fibrosis. Electron microscopically, the eosinophilic epithelium showed a marked increase in the number of rough endoplasmic reticula, ribosomes, mitochondria, and filamentous structures, suggesting an active viability of the cell. Subsequently, the eosinophilic cells were replaced by normal-appearing epithelium, not associated with the periductal fibrosis. The data suggest that an epithelial regeneration occurred in the intrahepatic duct following injury and that this activity may be similar to that of the extrahepatic bile duct epithelium.

Animals↗
PubMed1986

Experimental mesangioproliferative glomerulonephritis in rats induced by intravenous administration of anti-thymocyte serum.

Focal glomerulonephritis was induced in rats, by a single intravenous injection of anti-Thy-1.1 antibody (ATS). One hour after the administration, the glomeruli of affected rats developed necrotic changes of the mesangial cells while after two hours, mesangiolytic changes appeared. From six days onwards, focal segmental mesangial proliferation which persisted until 30 days, occurred. This is thought to be the first report of experimental nephritis induced by pure anti-mesangial antibody.

Animals↗
PubMed1986

Histopathological study on the effects of aging in myocardium of hypertrophied hearts.

To clarify the effects of aging in myocardium of hypertrophied hearts, 555 autopsied hearts were studied histopathologically. Degrees of myocyte hypertrophy, disarrangement and fibrosis and lipofuscin deposits were estimated light-microscopically in tissue specimens taken from the anterior wall of the left ventricle. Myocyte hypertrophy was assigned to one of four classes from 0 to 3+ according to size. Other findings were estimated using the conventional three classes. All cases were divided according to heart weight, into the following groups: severe hypertrophy (Group I; more than 450 g for males and 400 g for females), mild hypertrophy (Group II; 450 greater than HW greater than 350 g for males and 400 greater than HW greater than 300 g for females) and no hypertrophy (Group III: less than 350 g for males and 300 g for females). Lipofuscin deposits increased with aging, but in Group I the increase was delayed in comparison to that in other groups. As a rule, myocyte size in the outer layer was equal to or smaller than that in the inner layer (outer-layer-selective atrophy). This was particularly true in pressure-overloaded hypertrophy and less so in volume-overloaded hypertrophy. Myocyte disarrangement was observed in the inner and median layers in the oldest group. Peri-vascular fibrosis became thick with aging, and perimysial fibrosis increased with age. The fibrotic process was accelerated in hypertrophied myocardium. As to the mode of hypertrophy, aging appears to result in a kind of myocardial asymmetry of layer-selective atrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Binding sites of calcitonin gene-related peptide (CGRP): abundant occurrence in visceral organs.

Calcitonin gene-related peptide (CGRP) is a novel peptide amide of 37 amino acid residues, which was first identified as the product of alternative processing of RNA transcripts of the calcitonin gene in humans and rats. Using 125I-human CGRP (hCGRP) as the binding ligand and hCGRP or salmon calcitonin (sCT) as the specific inhibitor of binding, it was examined how the receptor-like binding sites distribute among rat tissues including the nervous system, which is already known to contain binding sites in discrete regions. Some visceral organs (liver, spleen and lung) and possibly the bone marrow of Wistar male rats (8-10 weeks old) were found to be relatively rich in these binding sites. The following parameters were calculated by Scatchard analysis of binding data for the cerebellum, spleen and liver; KD (nM) and Bmax (fmol/mg protein) were 0.61 and 408, 1.08 and 858, and 0.89 and 356, respectively. In these three tissues, both hCGRP and sCT were able to completely suppress the specific binding; the IC50s (nM) of hCGRP for the cerebellum, spleen and liver were 2.57, 2.29 and 3.02, respectively, and the IC50s (microM) of sCT 2.69, 0.41 and 1.78, respectively. The results obtained herein strongly suggest the physiological function of CGRP in these visceral organs including bone marrow.

Animals↗
PubMed1986

Magnetocardiographic P waves in normal subjects and patients with mitral stenosis.

The P wave of the magnetocardiogram (MCG) was investigated in normal subjects and patients with mitral stenosis to determine its characteristics in normal conditions and left atrial overloading (LAO) and to analyze atrial activation by a magnetic field. In normal subjects, the MCG P wave was negative in left parasternal sites and positive in right lower sternal sites. The current source deduced from the MCG pattern and isomagnetic map was directed inferiorly and to the left through the entire phase of atrial activation, suggesting that in most normal cases the P wave reflects right atrial activity. In patients with mitral stenosis, a negative-positive biphasic P wave was seen more frequently than in normal subjects in left parasternal sites (p less than 0.005). In the late phase of atrial activation, the current source deduced from the isomagnetic map was shifted superiorly and to the left, suggesting an increased leftward force due to LAO. The MCG was similar in sensitivity to the ECG, for diagnosis of LAO, but in a few cases LAO could be detected from the MCG but not the ECG. These findings suggest that the MCG is clinically useful for diagnosis of LAO.

Adult↗
PubMed1986

Increased dependency of cardiac pacemaker activity on extracellular Ca after adrenergic blockade in the frog heart.

The frog sinus venosus shows spontaneous regular pacemaker activity, even in the absence of extracellular Ca2+. When an alpha-adrenergic blocking agent (phentolamine) is applied, the rate of pacemaker activity, height of action potential, rate of slow diastolic depolarization, and the maximum diastolic potential become strongly dependent upon the extracellular Ca2+ concentration.

Adrenergic Fibers↗
PubMed1986

Mechanism of spontaneous rhythmic contraction in isolated rat large artery.

The mechanism of spontaneous contraction of vascular smooth muscles in the elastic artery was studied in a ring-shaped preparation isolated from the rat aorta. The observation of small changes in vascular tension with a high gain AC amplification of tension signal provided a reliable detection of spontaneous contractions. The spontaneous rhythmic contraction (RC) occurred consistently in the preparation taken from the thoracic aorta without external stimuli. The RC (frequency, 5-20 cycle/min; amplitude, 10-100 mg) was accompanied with small oscillatory changes in the membrane potential (2-5 mV, peak to peak). A reduction in temperature (below 30 degrees C) or superfusing the preparation with Ca-free solution inhibited the generation of RC. Ca-entry blockers (verapamil and nifedipine) also inhibited the RC. The cessation of RC by these procedures reduced the vascular tension by about 40% of control baseline tension. The application of adrenergic blockers had little effect on the pattern of RC and on the vascular tension. The results suggest that the RC is generated by a synchronization of electrical and mechanical activities in relatively small groups of smooth muscle cells, which depends upon the temperature and requires the Ca-entry into the cells. The process of initiation of spontaneous RC in the rat aorta was discussed.

Animals↗
PubMed1986

[Foreign bodies of unknown origin found in a serosal hematoma between the stomach and the pancreas of a patient].

An autopsy of a 55-year-old man who had died suddenly revealed extensive intra-abdominal bleeding and a serosal hematoma between the stomach and the pancreas, in which numerous foreign bodies were found. They were located just adjacent to pancreatic tissue which had undergone changes of acute necrotizing pancreatitis. It was assumed that they had been shaped by a pathological mechanism contributing much to the sudden death of the patient. The nature of the foreign bodies was investigated by comparing their microscopic sections with those of various living organisms and by testing their chemical character with some histochemical methods. However, they had no similarities to known foreign bodies of animal or plant origin found in pathological sections of human tissues and no conclusive evidence on their chemical nature could be obtained either. Our unified opinion is that the foreign bodies might have been formed in human tissues in situ as a result of the pathological tissue changes. The morphological features of the bodies are described in detail and their significance is discussed.

Acute Disease↗