Search PubMed⌕ Search

Biomedical subjects

S Isomura

Publications and source records attributed to S Isomura.

At least 91 records · Page 5Linked to original sources
PubMed1985

On the intracellular transport and the nuclear association of human cytomegalovirus structural proteins.

In cells productively infected with human cytomegalovirus (HCMV) AD169, large amounts of two viral proteins, the 150K major capsid and the 68K major matrix proteins, are continuously produced during the late phase of infection. In the present study, the mechanism for the intracellular transport of the 150K and 68K proteins was investigated. Infected cells were labelled for 30 min at 72 h post-infection with [35S]methionine, chased for various periods of time at 37 degrees C, and fractionated into cytoplasmic and nuclear fractions. Immediately after 30 min of labelling, the 68K protein was already associated with the nuclear fraction. In contrast, the major proportion of the 150K protein remained in the cytoplasm for more than 1 h; the migration of the 150K protein was much slower than that of the 68K protein. Both the 150K and the 68K proteins were associated with the perinuclear cytoskeletal fraction in the process of migration. After migration into the nucleus, these proteins were resistant to extraction with DNase and high salt, indicating that they were associated with the nuclear skeleton (nuclear matrix). Effects of various inhibitors on the migration of the 150K protein showed that cycloheximide inhibited the transport of the 150K protein, but other inhibitors such as arabinosyl cytosine, cytochalasin D, colchicine or sodium azide did not. The results suggest that the cytoskeletal structure may play a role in the intracellular transport of HCMV structural proteins from the cytoplasm into the nucleus.

Biological Transport↗
PubMed1985

Treatment of subacute sclerosing panencephalitis with human leukocyte interferon.

In five patients with subacute sclerosing panencephalitis (SSPE), human leukocyte interferon (IFN) therapy was tried. IFN was administered intramuscularly, intravenously, and intrathecally. The total dose of administered IFN ranged from 13 X 10(6) to 116.92 X 10(6) IU. There were no severe side effects except for temporary high fever and vomiting. Observation of the clinical course were made for 26-60 months. At the beginning of the treatment, one of the patients was at the first stage of Jabbour's classification and the other four at the second stage. No clinical improvement was observed and the clinical course was progressive in all patients. At present, one of the patients was at the second stage and the other four were at the fourth stage. EEGs showed progressive deterioration, and cranial CT scan demonstrated progressive cortical atrophy and ventricular enlargement. Measles antibody titers in the serum and CSF also unchanged. On the other hand, permeability of IFN at blood-brain barrier (BBB) was relatively good.

Child↗
PubMed1985

Clinical and serological reactions after immunization of children in Ghana, West Africa, with the Japanese acellular pertussis vaccine.

A sero-epidemiological survey of pertussis and a field trial with acellular pertussis vaccine was carried out in children in a rural village in Ghana, West Africa. ELISA antibody assays in 109 children aged three months to three years disclosed the rapid disappearance of transplacental maternal antibody in early infancy and the accumulation of seronegative children under three years of age. One hundred and ten children aged three months to three years were immunized with the newly developed acellular pertussis vaccine; 32 were immunized twice and 77 were immunized three times. Serological responses after immunization were measured in both groups. There were no severe adverse reactions attributable to vaccine injections among the children studied.

Antibodies, Bacterial↗
PubMed1985

Clinical efficacy of the Japanese acellular pertussis vaccine after intrafamiliar exposure to pertussis patients.

A major increase in the number of pertussis cases was observed subsequent to the complete discontinuation of mass-immunization against the disease in Aichi Prefecture in central Japan. The discontinuation of DTP vaccine started in 1975 and lasted for five years. Since 1978, epidemics of pertussis were observed in children mainly in the unvaccinated age groups. The outbreaks continued in the following year and subsided in 1980 when vaccination was reintroduced. Since 1981 newly developed acellular pertussis vaccines have been used for mass-immunization. The incidence of pertussis has remained low and no epidemics of the disease have been observed among children vaccinated with the new vaccines. During the epidemics in Aichi Prefecture, the protective efficacy of the new vaccines were studied in 21 vaccinees with intrafamiliar exposure to the disease. Clinical observations showed that the vaccine reduced the attack rate of pertussis after household contacts from 85% to 9.5%. It was concluded that the vaccine effectively prevented pertussis.

Child↗
PubMed1984

Seroepidemiological study of rotavirus infection in rural Ghana.

Children in a village in rural Ghana were found to have acquired antibody to rotavirus by the age of two years. The results of our study suggest that primary infection takes place early in infancy. Fifty-six per cent of the three to 20-months-old had a four-fold rise in antibody levels during the six months follow-up period and 72.2% of them had one or more episodes of diarrhoea compared with 42.8% of those whose antibody levels stayed the same or decreased. The major epidemic season is considered to be the dry season.

Antibodies, Viral↗
PubMed1984

Passive immunization against varicella in sick neonates by transfusion from donors immunologically enhanced by previous vaccination with live varicella vaccine.

Twenty-six sick children in a neonatal unit received passive immunization against varicella shortly after close contact with varicella in the ward, with the aim of preventing nosocomial infection. Because zoster immune globulin was not available at the time, the babies were given transfusion of whole blood from donors. All these donors had a history of varicella in childhood, and had received live varicella vaccine, Oka strain, to increase their immunological status before use of their blood for transfusion. Only one of the recipients contracted varicella after the passive immunization. No adverse reaction attributable to the transfusion was observed.

Antibodies, Viral↗
PubMed1983

Monoclonal antibodies to the HN glycoprotein of Newcastle disease virus. Biological characterization and use for strain comparisons.

We have isolated nine hybridomas secreting monoclonal antibodies directed against the HN glycoprotein of D26 strain of Newcastle disease virus (NDV) and classified them into three groups by their biological reactivities. The group I antibodies from six clones had high hemagglutination inhibition (HI) and neutralization titers, and exhibited neuraminidase inhibition (NI) activity with substrates, both bovine fetuin and N-acetyl neuraminlactose, although the levels of maximum inhibition were greater with the former substrate. The group II antibodies from two clones also had high HI activity but showed a strongly substrate-dependent NI, with efficient inhibition against fetuin and a total lack of inhibition against neuraminlactose. These antibodies had neutralization capacity but the titers were much lower than those of group I antibodies. One clone (group III) secreted antibody which exhibited HI and NI with either substrate but no detectable neutralization activity. Frequency of isolation of antigenic variants and competitive binding assays have shown that group I and group II antibodies may recognize distinct regions not overlapping each other whereas antibodies placed within each of the two groups are to the respective same overlapping regions. The site of group III seemed to be close to or overlap the group I determinant but distinct from group II region. Using the isolated monoclonal antibodies we compared seven heterologous strains by HI and neutralization tests as well as by enzyme-linked immunosorbent assay. The results indicated that the regions recognized by group I antibodies would be conserved among the strains whereas those by the other two antibody groups might undergo considerable changes.

Antibodies, Monoclonal↗
PubMed1983

Local T cell subsets in mumps meningitis.

In the acute phase of mumps meningitis, more than 85% of the cells in cerebrospinal fluid (CSF) were OKT 3 positive, while 76% of the peripheral mononuclear cells (PMN) were OKT 3 positive. The ratio of OKT 4:8 positive cells in CSF was significantly lower than that in PMN, showing that suppressor/cytotoxic T cells had selectively accumulated in CSF. In addition, 58% of CSF cells were immune associated (Ia) positive, probably activated T cells.

Cerebrospinal Fluid↗
PubMed1983

Epicardial activation patterns and dispersion of refractoriness initiating ventricular tachycardia in the canine left ventricle during acute ischemia.

We examined the activation patterns in the left ventricular epicardial surface of dog hearts using multielectrode grid during the beats initiating ventricular tachycardia 5 to 120 min after coronary artery occlusion. The grid was placed on the ischemic border zone (the area was confirmed by ST-isopotential mapping) to record simultaneously 36 unipolar epicardial potentials. Under the control conditions almost radial spread of activation from the central stimulating electrode of the grid was observed. Activation during acute ischemia showed crowded isochrone lines in the ischemic area, especially during the premature beats with shorter coupling intervals. In 8 out of 15 episodes, where ventricular tachycardia was induced by a single premature stimulus, the conduction delay during premature beats culminated in the local conduction block accompanied by circus movement of activation. Subsequent initial beats of ventricular tachycardia also showed similar activation patterns indicating reentry of excitation. In the remaining 7 episodes, however, we could not obtain such circus movement of activation under the grid. We also measured the effective refractory period at 5 sites under the grid. The results showed greater dispersion of the effective refractory period in the ischemic border zone throughout 5 to 120 min after coronary occlusion in the cases where ventricular tachycardia developed. These findings suggest that reentry of excitation, which is most probably caused by inhomogeneity of refractoriness in the ischemic border zone, may play an important role in the genesis of ventricular tachyarrhythmias during acute ischemia.

Animals↗
PubMed1982

Correlation between body surface isopotential maps and left ventriculograms in patients with old inferoposterior myocardial infarction.

In 24 patients with old inferoposterior myocardial infarction, body surface isopotential maps were compared with left ventriculographic findings. In 16 patients with asynergy restricted to the inferior and/or posterolateral segment, surface potential abnormalities due to infarction were observed during specific phases of QRS and in specific portions on the chest surface depending on the location and extent of ventricular severe asynergy (akinesis and dyskinesis). However, the remaining eight patients with coexisting severe asynergy in the anterior, apical, or septal segment showed surface potential maps quite different from those of the former patients. It is suggested that body surface isopotential maps are a useful clinical tool for detecting the location and extent of ventricular severe asynergy in patients with old inferoposterior myocardial infarction.

Aged↗
PubMed1982

Role of viral glycoproteins in haemolysis by influenza B virus.

Influenza B virus exhibited haemolytic activity at low pH, but the pH profile for its activity varied from strain to strain. The results of selective heat-inactivation of the enzyme activity of neuraminidase (NA) or elimination from virions of the enzyme-active portion of the NA molecule by trypsin digestion, suggest that proteolytically cleaved haemagglutinin, but not enzyme activity of NA, is essential for haemolysis by influenza B virus.

Animals↗
PubMed1982

Studies on live attenuated mumps vaccine. III. Long-term follow-up study on the efficacy of Biken vaccine.

Clinical and serological follow-ups were made on 24 children for 8 years after immunization against mumps with attenuated mumps vaccine, Biken vaccine. To evaluate the protective efficacy of the vaccine, matched controls were studied during the same period. Serological examination revealed that 91% of the controls were infected with mumps and 83% of them contracted the disease during the studied period. However, none of the vaccinees developed clinical infection after close contact with mumps patients. There was no substantial decrease in the antibody titers in unexposed vaccines after vaccination.

Antibodies, Viral↗