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Biomedical subjects

T Kurata

Publications and source records attributed to T Kurata.

At least 343 records · Page 19Linked 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

Detection of viral antigens in formalin-fixed specimens by enzyme treatment.

Enzyme treatment (protease or trypsin) was applied to formalin-fixed paraffin-embedded materials and virus-infected cultured cells to detect viral antigens by immunofluorescence. The viral antigens were demonstrated in several organs of autopsy or biopsy cases of which diagnoses had been established by immunofluorescence or virus isolation using frozen materials, or suspected on the basis of serology and/or histopathological findings. These included herpes simplex, varicella-zoster, cytomegalo, subacute sclerosing panencephalitis, progressive multifocal leukoencephalopathy, Japanese B encephalitis, measles, acute hemorrhagic conjunctivitis, Lassa and Korean hemorrhagic fever. Antigen could be recovered also in virus-infected cells (herpes simplex, measles, Lassa, Ebola, Marburg, Rift Valley, Congo and Korean Hemorrhagic fever) by enzyme treatment after periods of formalin fixation of four weeks and storage of three months. In herpes simplex virus-infected mouse brain, antigen was detected after fixation for three months in formalin.

Adolescent↗
PubMed1983

Immunofluorescence studies of disseminated Hantaan virus infection of suckling mice.

Hantaan virus, the etiological agent of Korean hemorrhagic fever, was inoculated intracerebrally or intraperitoneally into suckling mice, and the course of the infection was followed by infectivity titration and immunofluorescence studies. Mice became ill and were moribund by 13 to 14 days postinfection. In mice inoculated either intracerebrally or intraperitoneally, virus antigen was present in brain, heart, lungs, liver, and kidney. Less consistently, specific fluorescence was observed in spleen, pituitary gland, thymus, lymph nodes, adrenal, pancreas, salivary glands, trigeminal ganglia, adipose tissue, intestine, and muscle. In all of these tissues, the primary target of infection was the capillary endothelium. In mice inoculated intracerebrally, virus antigen was present mainly in choroid plexus, hippocampal nuclei, and meninges, but in mice inoculated intraperitoneally, central nervous system infection was marked by antigen accumulation in cortical nuclei and thalamus.

Animals↗
PubMed1983

Isolation of hemorrhagic fever with renal syndrome (HFRS) virus from a tumor specimen in a rat.

A strain of hemorrhagic fever with renal syndrome (HFRS) virus was isolated in a cell culture from a tumor specimen in a rat kept in a medical institution in which there was a case of HFRS. Positive immunofluorescent reaction with sera from HFRS patients was recognized at the second passage and the number of cells containing antigen increased in the third passage. This virus, named B-1 strain, was identified as the HFRS virus by immunofluorescent tests with sera from patients.

Animals↗
PubMed1983

[Effect of ara-A on the experimental herpes simplex virus encephalitis--pathology and fluctuation of the cerebrospinal fluid and serum antibody levels].

The effect of Ara-A treatment on the experimentally induced herpes simplex virus (HSV) encephalitis in rabbits was examined. Simultaneously practical value of enzyme-linked immunosorbent assay (ELISA) for rapid diagnosis was tested to find an early rise of antibody in cerebrospinal fluid (CSF) and serum in connection with an adoption of Ara-A administration. HSV encephalitis was produced by inoculation with type-1 HSV into the bilateral corneas of the eyes. A large amount of pus and typical neurological signs characteristic to encephalitis appeared after several days of infection. Ara-A therapy begun at the 3rd day of infection clearly increased the survival rate (90%) and improved the clinical signs, but the start of the drug at the 6th day could only increase the survival rate (60%) without cure of the clinical symptoms. ELISA could catch the early rise of IgG antibody in CSF from 3-4 days and in serum from 4-6 days after infection. Ara-A didn't interfere the antibody production. Viral antigens were found in the corneal epithelia and propria, neurons and Schwann's cells of trigeminal ganglia, neurons and glial cells of pons and cerebrum, especially in hippocampal nuclei. Typical Cowdry A and full type intranuclear inclusion bodies in the neurons were observed in the above tissues with infiltration of large amount of small round cells. In conclusion, Ara-A therapy in HSV encephalitis at the early stage of infection was quite effective for cure and the ELISA method is a useful tool for detection of early antibody rise in CSF and serum.

Animals↗
PubMed1983

Case report of adult T-cell leukemia with preceding long-standing cutaneous involvement.

This report documents an unusual case of adult T-cell leukemia (ATL) with a preceding phase of long-standing cutaneous involvement. After nine months of an aleukemic phase, characteristic leukemic cells of ATL, possessing inducer/helper phenotype without helper function, had appeared. In addition, antibodies to ATL virus-associated antigen (ATLA) were found in the serum of the patient and her family. The patient died after an 18-month clinical course due to generalized cytomegalovirus infection in spite of strong chemotherapy. At autopsy, leukemic involvement was restricted to the skin. We postulate that ATL may originate not only from the lymph nodes but also from the skin.

Aged↗
PubMed1982

Enzymatic treatment of formalin-fixed and paraffin-embedded specimens for detection of antigens of herpes simplex, varicella-zoster and human cytomegaloviruses.

Attempts were made to detect antigens of herpes simplex (HS), varicella-zoster (VZ) and human cytomegalo (CM) viruses in pathological preparations made by formalin fixation and paraffin embedding as well as in infected culture cells by means of enzymatic treatment followed by indirect immunofluorescent staining, and the following results were obtained. 1) Specimens from autopsy cases, in which diagnosis was established by detection of viral antigens or virus isolation, showed specific antigens in specimens of various organs of all cases of HS (6 cases), VZ (3 cases) and CM (2 cases). In 17 other cases, which were suspected for those viral infections on the basis of ordinary light microscopic observation, also demonstrated respective viral antigens specifically, enabling differential diagnosis. In one case, HS antigen was detected in the esophagus and CM antigen in the liver, testifying occurrence of a double infection. 2) The time spun during which the specific antigens could be preserved was tested, and it was learned that preservation of stainable antigens was better in paraffin-embedded specimens than in specimens kept in formalin. It was possible to detect HS and VZ antigens in paraffin-embedded specimens prepared 20 and 18 years ago, respectively. 3) The optimal conditions of trypsin treatment varied depending upon the organ as well as upon each individual specimen, but a commonly recommendable procedure was found to by warming at 37 degrees C for 3 hours with 0.25% trypsin. A test with HS virus-infected Vero cells indicated that the effect of trypsin treatment was influenced by the concentration of formalin and the time of fixation.

Antigens, Viral↗