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Biomedical subjects

J Fukuda

Publications and source records attributed to J Fukuda.

At least 163 records · Page 9Linked to original sources
PubMed1983

Specific reduction in Na currents after infection with herpes simplex virus in cultured mammalian nerve cells.

Tissue-cultured nerve cells originating from dorsal root ganglia of adult guinea-pigs were infected with type 2 herpes simplex virus (HSV) in vitro, and changes in membrane properties were examined (48 h later) by conventional electrophysiological technique using a glass microelectrode. The nerve cells infected with HSV (HSV-NC) failed to generate full-sized Na spikes, which was associated with a marked reduction in the maximum rate of rise of the Na spike, i.e. Na currents. Some SV-NC failed to generate any Na spike. By contrast, the HSV-NC generated unchanged, full-sized Ca spikes when bathed in a Na-free solution containing tetraethylammonium+. Changes in resting membrane properties, such as resting potential, input resistance and capacitance, remained small after the infection. We thus consider that HSV reduces Na currents in a specific fashion in this early period of the infection.

Animals↗
PubMed1983

Morphological and physiological studies on cultured nerve cells from guinea pigs infected with herpes simplex virus in vivo.

Adult guinea pigs were inoculated with type 2 herpes simplex virus (HSV) on the whole back skin, and nerve cells from the dorsal root ganglia (DRG) 6 days after infection were grown in tissue culture. Morphological and physiological properties of the cultured nerve cells from HSV-infected animals (HSV-NC) were compared to those of nerve cells of DRG from the control, non-virus infected animals (CON-NC). During the early period of the culture (0-4 days) growth of nerve cells and non-neuronal cells from the HSV infected animals was essentially the same as that from the control animals. HSV-antigen was present in only a small percentage of the HSV-NC by immunofluorescence (IF). Electrophysiological examination revealed that most of the HSV-NC exhibited a reduced capability of generating spikes, which was quantitatively described as a reduction in the Vmax of the Na spikes. This was interpreted as a reduction in the number of Na channel molecules in the plasma membrane of the HSV-NC, while the resting membrane properties of the same cells, such as the resting membrane potential, input resistance and capacitance, were essentially the same as those of the CON-NC. On 4-5 days in culture, some HSV-NC regained a full capability to generate Na spikes. We considered these nerve cells to have overcome the HSV infection and were now entering a latent period of HSV infection. About 1/3 of the HSV-NC still remained incapable of generating Na spikes. Viral antigen was detected in only 10% of the nerve cells. In the late stage of the culture, HSV infection in vitro was first observed as lysis of non-neuronal cells growing close to some HSV-NC. Nerve cells then started to lose their neurites and became spherical. Finally on 8-9 days most of the cells, including the nerve cells, were lost from the dishes as a result of a generalized infection of supporting cells, i.e. fibroblasts and Schwann cells. This study confirms our previous finding that the electrophysiological technique is much more sensitive than the IF method for the detection of HSV-infection in nerve cells. The results indicate that some nerve cells infected with HSV overcome the infection in vitro. This is interpreted as the entering of these nerve cells into a latent period of HSV infection in vitro.

Animals↗
PubMed1983

ATP content in isolated mammalian nerve cells assayed by a modified luciferin-luciferase method.

ATP content in a nerve cell isolated from dorsal root ganglia of adult guinea-pigs by collagenase was measured by a newly developed technique modified from the conventional luciferin-luciferase methods. A small volume (4 microliters) of the nerve cell suspension, which contained 10-300 nerve cells (3-100 X 10(-4) microliters of cellular volume) under view of an inverted, phase-contrast microscope, was heat-treated for about 1 s by flame of an alcohol lamp. This heat-treated cell suspension was then reacted with a luciferin-luciferase solution. Light flux from the bioluminescence thus elicited gave an ATP content in single nerve cell, 27 pg (mean) +/- 10 pg (S.D.). ATP concentration in a nerve cell was calculated as 1.7 mM (mean) +/- 0.6 mM. The ATP content in a nerve cell was reduced when the nerve cells were exposed to KCN (5 microM) or dinitrophenol (20 microM), respectively.

Adenosine Triphosphate↗
PubMed1983

[Neoplastic cardiac tamponade].

Pericardial metastases are frequently found and often cause cardiac tamponade which requires emergency treatment. Pericardiocentesis or subxiphoid pericardiotomy and pericardial drainage can be performed; the latter is a safe and effective method for the management of continuous pericardial effusion since it can be done under direct visualization and local anesthesia. We had four patients with neoplastic cardiac tamponade who were treated successfully with subxiphoid pericardiotomy and pericardial drainage. In three of them neoplasms had not been found until cytology of pericardial fluid proved to be malignant when they were attacked by cardiac tamponade. If the patient with malignancy is attacked by cardiac tamponade, subxiphoid pericardiotomy and pericardial drainage should be performed considering neoplastic cardiac tamponade. We have described pathophysiology, diagnosis and treatment of neoplastic cardiac tamponade.

Adult↗
PubMed1982

Distribution of beta-D-glucuronidase in the central nervous system of albino rats.

The distribution of beta-D-glucuronidase (GLR) in the central nervous system of albino rats was surveyed with a simultaneous-coupling histochemical technique. Specific neuronal populations displayed intense GLR activity. These groups include olfactory bulb mitral cells, neurones in the deep layer of the olfactory tubercle, cells in both the horizontal and vertical limbs of the nucleus of the diagonal band, paraventricular, supraoptic and suprachiasmatic nuclear neurons, cochlear and vestibular nuclear neurons, and facial, trigeminal and spinal motoneurons. Two types of intracellular GLR staining were observed. Granular staining was prominent in mitral cells; cytoplasmic staining and a perinuclear 'ring' were prominently stained in motoneurons. These patterns may correspond to lysosomal and endoplasmic reticular distribution of GLR in different cell types.

Animals↗
PubMed1982

Glycogen aggregates in cardiac muscle cell: a cytopathological study on endomyocardial biopsies.

Glycogen aggregates in the cardiac muscle cell, which have been frequently demonstrated in endomyocardial biopsies under the transmission electron microscope, were studied using the optical microscope in order to clarify their histopathological significance in various heart diseases. The right ventricular muscle biopsies were obtained from the following 120 patients: 24 cases of congestive cardiomyopathy, 26 of hypertrophic cardiomyopathy, 28 of atrial septal defect, 6 of primary pulmonary hypertension, 31 of bradyarrhythmic hearts and 5 controls. The tissue specimens were fixed with glutaraldehyde and osmium tetraoxide, and embedded in epoxy resin. Semi-thin sections from these specimens were dyed with tribasic staining originated by KUROTAKI (1972). Under the optical microscope, glycogen is clearly identified by its forming red stained areas which are seen not only in the subsarcolemmal layers and the perinuclear region, but also in the intermyofibrillar zones. The glycogen aggregates are more frequently observed in the specimens from the atrial septal defects and the bradyarrhythmic hearts than in the other cases. Thus, observation of glycogen aggregates reveals notable differences in appearance depending on the kinds of diseases. In the bradyarrhythmic hearts, the glycogen aggregates can be more readily observed in specimens from younger patients than in elderly ones. Furthermore, the glycogen aggregates appear regardless of both the grades of hypertrophy and degeneration in myocardial cells. These results do not agree with previous reports that the occurrence of glycogen is proportional with the grade of cardiac cell hypertrophy and/or damage.

Adult↗
PubMed1981

Electrophysiological properties of tissue-cultured nerve cells from senescent mouse.

Nerve cells were isolated from dorsal root ganglia of senescent mouse (C57 black, male) by collagenase and were grown on collagen-coated plastic dishes. The nerve cells extended their neurites and survived for more than 3 weeks in vitro. Intracellular recording with a glass microelectrode revealed that, although their resting membrane potential was small, the tissue-cultured nerve cells recovered membrane excitability after continuous hyperpolarization by DC current passage. Both Na and Ca spikes were elicited in thus hyperpolarized nerve cells. Some nerve cells generated tetrodotoxin-resistant Na spikes.

Action Potentials↗
PubMed1981

Loss of membrane excitability after herpes simplex virus infection in tissue-cultured nerve cells from adult mammals.

Dorsal root ganglion cells of adult guinea-pigs in vitro were inoculated with herpes simplex virus (HSV). Intracellular recording with a glass microelectrode revealed that HSV-infection caused a marked decrease in membrane excitability of the nerve cells within 24 h, which could be explained as a decrease in Na+ channel activity in the plasma membrane; while changes in other physiological properties (resting membrane potential, membrane resistance and capacitance) remain small. Viral antigens were detected in only 10-15% of the HSV-infected nerve cells. These indicate that the loss of the membrane excitability occurs much earlier than any other change in the HSV-infected nerve cells.

Animals↗
PubMed1980

A tissue-culture of nerve cells from adult mammalian ganglia and some electrophysiological properties of the nerve cells in vitro.

A new technique for primary culture of nerve cells isolated from peripheral ganglia of adult mammals has been developed. Nerve cells were isolated from trigeminal ganglia, nodose ganglia, sympathetic ganglia or dorsal root ganglia of adult guinea pigs by collagenase or dispase, and then were grown on collagen-coated plastic dishes for more than 4 weeks. Intracellular recording with a glass microelectrode reveals that the nerve cells in vitro generate not only Na spikes but also tetrodotoxin-resistant Na and Ca spikes. An exception was that the sympathetic ganglion cells in vitro failed to generate tetrodotoxin-resistant Na spikes. Difference in values of the Vmax of these spike components is observed among nerve cells (3-8 days in vitro) of different origin, suggesting that distribution of ionic channels on the plasma membrane may be different among species of nerve cells.

Animals↗