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Biomedical subjects

S Isomura

Publications and source records attributed to S Isomura.

At least 109 records · Page 6Linked to original sources
PubMed1982

The preventive effect of human interferon-alpha on influenza infection; modification of clinical manifestations of influenza in children in a closed community.

A double-blind, controlled trial to ascertain the preventive effect of human interferon-alpha (Hu IFN-alpha) on upper respiratory viral infections was performed on children in a closed community. Drops of Hu IFN-alpha were instilled into the nasal cavity of 13 healthy children aged one to three years. Fourteen children were given placebos as controls. Administration of the interferon and clinical observations were carried out in the winter of 1980. Serological examination revealed that this was the period of outbreaks of influenza type A epidemics in the community. Clinical manifestations referable to influenza virus infection were milder in the interferon-treated group than in the controls. However, there was no significant difference in the serological responses of the two groups after infection with influenza virus type A.

Administration, Intranasal↗
PubMed1981

Effects of injury to the right ventricular conducting tissue of canine hearts on epicardial activation sequence and electrocardiograms.

The distal right ventricular conducting tissues of 45 canine hearts were experimentally interrupted in various degrees by a transmural incision of the right ventricular free wall, a trans-section of the lateral branches of the right bundle or by injury to the endocardial Purkinje network. Right ventriculotomy caused a slight activation delay (less than 10 msec) of the right ventricle which was restricted to the distal area from the incision, but the delay was not long enough to cause a significant prolongation of the QRS duration in the limb lead ECG. In one experiment, a vertical incision in the middle region induced an exceptional, marked alteration of the right ventricular activation sequence and an apparent prolongation of the QRS duration (16 msec) indicating an incomplete RBBB. However, anatomical analysis revealed that the lateral branches were nearly completely interrupted by the incision. An extensive injury to the Purkinje network extending toward the right ventricular outflow tract by a blunt scalpel caused a local activation delay in the outflow tract, without producing any serious delay resulting in an ECG pattern of RBBB. These results may suggest that right ventriculotomy would induce the RBBB pattern of ECG if lateral branches are extensively injured by the surgical procedure, and that the injury to the Purkinje network extending toward the outflow tract does not play a primary role of genesis of RBBB pattern in ECG.

Action Potentials↗
PubMed1981

Body surface isopotential maps of experimentally induced transient right bundle branch block.

The characteristic patterns of the epicardial activation and body surface isopotential maps (MAPs) were examined in experimental transient right bundle branch block (RBBB) produced by pressing the main stem of right bundle mechanically. During the recovery from the complete block, various degrees of incomplete RBBB (IRBBB) were obtained. The epicardial activation of IRBBB spread in almost normal fashion with delayed right ventricular epicardial breakthrough. And the MAPs manifested intermediate patterns between those obtained in control and in complete RBBB (CRBBB). The MAP patterns of IRBBB were classified into the following 3 groups by the difference of the localized bend of isopotential lines reflecting the epicardial breakthrough. In the advanced IRBBB with QRS prolongation over 25%, the epicardial breakthrough of the left ventricle was detected on the MAPs. In the moderate IRBBB with QRS prolongation around 20%, in addition to the left ventricular breakthrough the right ventricular breakthrough was detected at the center of the anterior chest. In the mild IRBBB with QRS prolongation less than 15%, only the right ventricular breakthrough was detected. These findings indicate usefulness of MAPs for diagnosing the severity of IRBBB due to the damage to the main right bundle. Moreover, these MAP patterns in IRBBB of main right bundle can be distinctly differentiated from the IRBBB MAPs resulting from incisional interruption of lateral branches of right bundle. The present findings also suggest the usefulness of MAPs in diagnosing the site of the conduction disturbance resulting in IRBBB.

Animals↗
PubMed1981

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

In 30 patients with old anterior myocardial infarction, body surface isopotential maps were correlatively studied with left ventriculographic findings. In 25 patients with ventricular asynergy restricted to the anterior segments, surface potential abnormalities due to infarction were observed during specific phases of QRS and in specific portions of the chest surface depending on the location and extent of severe ventricular asynergy (akinesis and dyskinesis). However, the remaining 5 patients with co-existing severe asynergy in the inferoposterior segment, showed body surface potential maps quite different from those of the above 25 patients. It was suggested that body surface isopotential maps were useful in detecting the location and extent of ventricular severe asynergy in patients with old anterior myocardial infarction.

Adult↗
PubMed1980

Local immunity in mumps meningitis.

Titers of antibodies to mumps and measles virus and interferon activity were measured in sera and CSF obtained from 15 children with mumps meningitis. Antibody to mumps virus was found in 11 of 15 CSF samples. Evaluation of the CSF-serum ratio for antibodies to both viruses showed a substantially higher ratio for antibody to mumps virus. The ratio of IgG/IgM antibody activity to mumps virus was greater in CSF than in sera. These results could be attributed to antibody synthesis, particularly IgG, in the CNS. Titers of antibodies to mumps virus in CSF increased rapidly, reaching a peak four to ten days from onset of meningitis, and swiftly decreased thereafter. During the acute phase, interferon activity was found in almost all cases ranging from 16 to 128 IU/mL in sera, and 4 to 16 IU/mL in CSF. In cases of mumps meningitis that followed the usual clinical course, interferon disappeared within a week, whereas it persisted in the CSF in cases of persistent pleocytosis.

Antibodies, Viral↗
PubMed1980

Changes of the rotavirus concentration in faeces during the course of acute gastroenteritis as determined by the immune adherence hemagglutination test.

Concentrations of rotavirus were studied in serially sampled faecal specimens from 55 patients with acute gastroenteritis, utilizing the immune adherence hemagglutination (IAHA) test. Rotavirus antigen was detected in 45 (82%) out of 55 cases. In the faeces which were positive for rotavirus antigen, the concentrations reached their maximum titer shortly after the onset of the illness and diminished gradually until the 9th day.

Acute Disease↗
PubMed1980

Course of rotavirus gastroenteritis in a closed community.

There were 3 outbreaks of rotavirus gastroenteritis accompanied by milky-white stools in a closed community of 21 children in Japan during a 2-year period. Several different clinical courses were observed as a result of clinical, serological, and virological observations.

Child, Institutionalized↗
PubMed1980

[The effects of high copper amalgams upon L strain fibroblasts in vitro (author's transl)].

To investigate the cytotoxicity of three high copper amalgams (HA 1, HA 2 and HA 3) which are currently available in Japan, and compare with that of the conventional amalgams, i. e., fine cut, spherical and copper amalgams, a cell culture system with L strain fibroblasts was used. Results were assessed by cell multiplication rate calculated from cell nuclei counting and cell morphology. The results obtained were as follows: 1. Amalgam alloys of two of the high copper amalgams tested (HA 3 and HA 1) as well as two of the conventional amalgams, i. e., fine cut and spherical amalgams did not give adverse effects to the cells. However, the alloys of the other high copper amalgam, HA 2, and copper amalgam yielded intense cytotoxicity. 2. As to the triturated amalgams, two of the high copper amalgams (HA 3 and HA 1) showed a very similar effects to the cell to the fine cut and spherical amalgams. At three hours after trituration, depression of cell growth diminished in two of the high copper amalgams(HA 3 and HA 1). However, the other high copper amalgam, HA 2, yielded intense and persistent cytotoxicity even at 24 hours after after trituration. 3. Cell morphology of the experimental groups confirmed the above result of the rate of cell multiplication. 4. A similar biological effect to the results in several previous reports with three conventional amalgams in vitro was confirmed. It was discussed that difference of biological effects in vitro among the three high copper amalgams might be attributed to the alloy composition. It is considered that the present results will be able to lend suggestions to the use of the high copper amalgams.

Animals↗
PubMed1979

Echocardiographic evaluation of right ventricular anterior wall motion in the Wolff-Parkinson-White syndrome.

Echocardiographic motions of right ventricular anterior wall (RVAW) were investigated in 71 patients with Wolff-Parkinson-White (WPW) syndrome. According to the criteria of Rosenbaum et al the electrocardiograms were classified as type A in 35 patients and type B in 36. Sixteen type B patients exhibited abnormal RVAW motion, which was characterized by an early onset of the posterior movement before S1 andl also by a premature peak formation before S2. A small step or hump nearly coincident with S1 was observed in 10 of these 16 patients. These findings seem to suggest that both contraction and relaxation of RVAW begin earlier than normal due to anterior right ventricular pre-excitation. RVAW motion was normal in all of type A patients. Echocardiographic investigation of RVAW motion appears to be useful in non-invasive estimation of the site of pre-excitation, especially in type B WPW patients.

Adolescent↗
PubMed1978

Acute infantile gastroenteritis caused by rotavirus in Japan.

We had an outbreak of acute infantile gastroenteritis accompanied by milky-white stool (called Hakuri in Japanese) during the winters of 1976 and 1977. Stool specimens collected from 72 cases of Hakuri were studied by negative-staining electron microscopy. Rotavirus was detected with a very high frequency (89%). Rotavirus obtained from one of the patients was isolated and passaged in cultures of primary human embryonic kidney cells. Viral antigens could be detected in the cytoplasm of the cells by indirect immuno-fluorescence. The fluorescence-positive cells increased in number with repeated passage. Serum anti-viral activities in 11 patients were titrated by indirect immuno-fluorescence, using the cells infected with the passaged rotavirus. All 11 patients developed IgM responses in the convalescent phase. However, in 4 of the 11 patients, no IgG responses were detected even 2--3 weeks after the onset of illness. The reinfection which has occasionally be seen in our country may be related to these poor IgG responses.

Acute Disease↗
PubMed1978

An epidemiological study of subacute sclerosing panencephalitis in Japan, 1976.

The National Registry for subacute sclerosing panencephalitis (SSPE) of Japan was established in 1976 at the Research Institute for Microbial Diseases, Osaka University, under the auspices of the Ministry of Health and Welfare. By March 1977, forty five clinically confirmed cases of SSPE were reported to the Registry, with onset of symptoms occurring between 1966 and 1976. Histories of measles were available in 42 of these cases. Thirty nine patients with known histories had measles prior to onset of SSPE and 3 had no history of measles illness. Twenty eight (71.7%) of the 39 patients had measles before the age of 2 years. All cases were 1 to 14 years old at the time of onset of SSPE and the mean interval between measles and SSPE was 6.1 years. One of the 3 cases with no history of measles was a recipient of measles killed vaccine, but no case of SSPE was reported among recipients of measles live, attenuated vaccine.

Adolescent↗
PubMed1977

Protective efficacy of vaccination in children in four episodes of natural varicella and zoster in the ward.

It was previously reported that a live varicella vaccine (Oka strain) has been developed and that the immediate vaccination of hospitalized children was effective for prevention of spread of varicella in a ward. Six to nine months later, there were four separate episodes of varicella and zoster in the same ward. Eighteen children (11 with nephrotic syndrome, 6 with nephritis, and 1 with hepatitis) with no history of varicella were inoculated with a live vaccine before or immediately after admittance or occurence of the varicella and zoster cases. Twelve of them had been receiving steroid therapy and 15 of the 18 were found to be seronegative by complement fixation and neutralization tests before the vaccination. All of them became seropositive after vaccination without any clinical symptoms. The longest period between vaccination and exposure was nine months. None of the vaccinees exhibited varicella symptoms after exposure. Serological follow-up of ten vaccinated children was done, and booster responses were observed in some of them after exposure. These results suggest that the live vaccine affords immunity to the recipients. If hospitalized children are vaccinated before or immediately after exposure, isolation of the patient is unnecessary.

Adolescent↗
PubMed1977

[Effects of electrical stimulus upon L-strain cells. (Part 2)--Response of the cells to alternative current prior to cultivation (author's transl)].

In order to examine the effects of voltage, current time and frequency of the alternative current on cell multiplication and morphology during initial stage of cell cultivation, alternative currents of varying intensity were applied to the L-strain cells in the tissue culture medium, i.e. YLH solution supplemented with 5% bovine serum which was considered as an electrolyte solution. The following results were obtained: 1) The rates of cell multiplication depended on the frequency (0.01 Hz-10 KHz), when voltage and current time were kept constant. In particular, they were remarkably depressed in the low frequency range. In a certain frequency range, a maximum value of the rates of cell multiplication was recorded. It was considered that there is certainly a least inhibitive frequency range in the rates of cell multiplication. 2) The lower and the shorter the voltage and current time were, the lower were the frequency level at the threshold of marked inhibition of the rates of cell multiplication brought. 3) An arbitrary equation for the relationship between the rates of cell multiplication and frequency was determined: The rates of cell multiplication upon cell multiplication were proportional to (A + log F), where A was a constant value and F was the applied frequency. According to the equation above, the depression upon cell multiplication was calculated, when the values of voltage and current time were given. 4) It was found that the results of the rates of cell multiplication were parallel to the results of the morphological observations. It was presumed that the main factor governing cell multiplication during application of the alternative current was due to change of the compositions of medium which was electrolyzed.

Animals↗