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Biomedical subjects

M Iwanaga

Publications and source records attributed to M Iwanaga.

At least 127 records · Page 7Linked to original sources
PubMed1987

Enterotoxicity of El Tor-like hemolysin of non-O1 Vibrio cholerae.

The enterotoxicity of an El Tor-like hemolysin purified from non-O1 Vibrio cholerae was investigated. Fluid accumulation was induced by injection of purified hemolysin into the ligated intestinal loops in adult rabbits (De test), intraintestinal administration in infant rabbits (Dutta test), and oral inoculation in suckling mice. The accumulated fluid was invariably mucous and bloody, and a histological change in the mucosa was observed. These results suggest that the hemolysin is an enterotoxic factor that is responsible for non-O1 V. cholerae gastroenteritis.

Animals↗
PubMed1987

Large production of cholera toxin by Vibrio cholerae O1 in yeast extract peptone water.

A large amount of cholera toxin (CT) was produced by Vibrio cholerae O1 cultured in yeast extract-peptone water. The organisms were cultured initially in a stationary test tube (small surface-to-volume ratio) until the end of the exponential phase and subsequently cultured in a shaking flask for 15 to 20 h. By this method (previously reported as the AKI-SW method), most cholera vibrios produced an abundance of CT (up to 64 micrograms/ml), regardless of their biotype and serotype. A substantial amount of CT was produced even in basic peptone water (2% peptone, 0.5% NaCl). Use of sodium bicarbonate, which markedly stimulated CT production in the stationary test tube culture, was undesirable for CT production by the culture method used here. CT production was greatly influenced by culture conditions but was not significantly affected by the composition of the medium.

Cholera Toxin↗
PubMed1987

Traumatic lung pseudocyst.

Traumatic lung pseudocyst is an uncommon lung injury due to closed chest trauma. Four cases are reported; all were male and one was a child. Three cases showed spontaneous resolution of the pseudocyst and in one case, where resolution was slow, lobectomy was carried out at the patient's insistence. Diagnosis poses no serious problems as there is inevitably a history of substantial chest trauma. The chest radiograph shows a characteristic cavitatory lesion. The pseudocysts may be multiple. Tomography may be helpful in diagnosis and computed tomography can be particularly useful in the demonstration of paramediastinal traumatic pseudocysts.

Adult↗
PubMed1986

Culture conditions for stimulating cholera toxin production by Vibrio cholerae O1 El Tor.

A method that stimulates cholera toxin (CT) production by Vibrio cholerae O1 biotype El Tor (El Tor vibrios) to the level of several micrograms per ml in the culture fluid was established. Such a large amount of CT was obtained by the following method: El Tor vibrios were cultured in AKI medium (1.5% Bacto peptone, 0.4% yeast extract-Difco, 0.5% NaCl, 0.3% NaHCO3) at 37 C for 4 hr in a stationary test tube and then for 16 hr in a shaken flask, with inoculum sizes of 10(5) to 10(7)/ml. With this method, 35 strains out of 60 examined produced 2 to 16 micrograms/ml of CT as determined by the reversed passive latex agglutination test (RPLA). Thirty-three randomly selected strains out of the 60 produced reasonable amounts of rabbit skin vascular permeability factor, reflecting the amount of CT titrated with RPLA.

Bacteriological Techniques↗
PubMed1986

Identity of hemolysins produced by Vibrio cholerae non-O1 and V. cholerae O1, biotype El Tor.

Hemolysins purified from non-O1 Vibrio cholerae (non-O1 hemolysin) and a Vibrio cholerae O1, biotype El Tor (El Tor hemolysin) were investigated for their homology. The hemolysins were isolated from the culture supernatant fluids by ammonium sulfate precipitation and gel filtration on Sephadex G-100 columns. The purified hemolysins gave single bands with an identical mobility on conventional polyacrylamide gel disc electrophoresis. The molecular weights of the non-O1 and El Tor hemolysins were estimated to be about 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the amino acid compositions of the hemolysins were very similar. The specific activities of the hemolysins were identical, and both hemolysins were neutralized to the same extent with antisera against the homologous and heterologous hemolysins. Ouchterlony double immunodiffusion tests with both hemolysins and antihemolysin serum gave a common (fused) precipitin line. These data indicate that the non-O1 hemolysin is biologically, physicochemically, and immunologically indistinguishable from the El Tor hemolysin.

Amino Acids↗
PubMed1986

Ossiculoplasty failure with ceramic ossicular replacement prosthesis.

The stability of ceramic ossicular replacement prosthesis (CORP) in the middle ear was evaluated in 162 ears that had been followed for more than 18 months. The CORP extruded from 8 ears (4.9%) and was dislocated in 6 ears (3.7%). These failures were considered to be due mainly to postoperative tubal dysfunction and disease recurrence. CORP should not be used when such conditions can be anticipated.

Adolescent↗
PubMed1985

Prevalence of a human retrovirus in native Japanese: evidence for a possible ancient origin.

The origin of a human retrovirus (ATLV or HTLV-I) is, at present, unknown although carriers of the virus have been found in Japan, the Caribbean basin and Africa. By means of a sero-epidemiological study, the Ainu people of Hokkaido, located in the northernmost island of Japan, were shown to have antibody to the virus in high frequency. Since the Ainu are regarded as descendants of the pre-agriculture native population of northern Japan, this finding appears to indicate that the retrovirus was already present in the aboriginal Japanese of prehistoric times.

Adolescent↗
PubMed1985

New medium for the production of cholera toxin by Vibrio cholerae O1 biotype El Tor.

A new medium that stimulates in vitro production of cholera toxin by Vibrio cholerae O1 El Tor (El Tor vibrios) was developed. The medium contains 0.5% NaCl, 0.3% NaHCO3, 0.4% yeast extract, and 1.5% Bacto-Peptone. El Tor vibrios were cultured in a stationary test tube at 37 degrees C for 20 h. The culture supernatant was assayed for cholera toxin by a reversed passive latex agglutination method. Most vibrios grown in this medium produced 10 to 20 times more toxin than in traditional syncase medium. The number of live vibrios at the end of culture was about 10(8)/ml in the new medium (AKI medium) and about 10(10)/ml in the syncase medium. As a result, each individual organism in the new medium should have produced as much as 1,000 times more toxin than in syncase medium. Sodium bicarbonate was found to be the most important factor in toxin production by El Tor vibrios in the new medium. We recommend this new medium because of its high yield of cholera toxin and its technical simplicity.

Bicarbonates↗
PubMed1985

Tinnitus and/or hearing loss elicited by facial mimetic movement.

Temporary tinnitus and/or hearing loss elicited by contraction of facial mimetic muscles are often observed on the affected side in patients recovering from facial nerve paralysis and in those with facial spasm. In order to clarify the mechanism of this phenomenon, changes in auditory threshold and middle ear compliance during voluntary contraction of mimetic muscles were investigated. The results suggest that this type of tinnitus and/or hearing loss is due to nonacoustic contraction of the stapedial muscle synchronous with contraction of mimetic muscles.

Acoustic Impedance Tests↗
PubMed1985

[Epidemiological studies of adult T-cell leukemia virus in patients with adult T-cell leukemia (ATL) and ATL-related diseases in Hokkaido District of Japan].

Sera and peripheral blood lymphocytes in 40 clinical cases of adult T-cell leukemia (ATL) and 66 cases of mature T-cell malignancies in Hokkaido district, the most northern part of Japan, were examined for the infection with ATL virus (ATLV). All of the 40 ATL patients (100%) had antibodies to ATLV-associated antigen (ATLA) and 13 (19.7%) of the 66 patients with mature T-cell malignancies other than ATL were also positive for anti-ATLA. When the peripheral ATL lymphocytes were assessed after short time cultivation, both ATLA antigen and C type virus particles were detectable. In contrast to the high prevalence of ATLV antibodies in these patients, the positivity in 30,000 control individuals in this district was 0.73%. It was calculated that 8 patients of a 40,000 seropositive population are diagnosed annually as ATL in this particular northern part of Japan.

Adult↗
PubMed1985

[Prevalence of antibody to adult T-cell leukemia virus in Hokkaido District].

In order to investigate the spread of adult T-cell leukemia (ATL) virus in the inhabitants of ATL-non-endemic Hokkaido, we surveyed the antibodies to ATL-associated antigen (ATLA) in 29516 healthy individuals by indirect immunofluorescence test using MT-1 for target cell. Of the healthy inhabitants, only 219 individuals (0.74%) were anti-ATLA positive as carriers. Prevalence of anti-ATLA was 0.63% (111 of 17590) in males and 0.91% (108 of 11926) in females. This difference by sex is significant. In several regions, the inhabitants were found to show relatively high incidence (greater than 2%) of the antibodies, and these regions have a tendency to cluster around the western side of Hidaka mountains or Akan area. The highest rate (5.2%) of anti-ATLA positive carriers was shown in a certain town of Hidaka area.

Adolescent↗
PubMed1985

[High prevalence of adult T-cell leukemia virus infection in family members of adult T-cell leukemia patients in non-endemic Hokkaido District].

Family members of non-endemic Hokkaido patients with adult T-cell leukemia (ATL) were assessed for the prevalence of ATL virus (ATLV) infection. Immunofluorescence test showed that 53 (39.8%) of 133 healthy family members of 23 ATL patients were positive for antibodies of ATLV-associated antigen (ATLA). When seropositive T-cell malignancies other than ATL and healthy controls in Hokkaido were examined, 10 of 33 family members (30.3%) of 9 patients and 3 of 18 family members (16.7%) of 5 donors had ATLA antibodies, respectively. In sharp contrast, the overall seropositivity in this northern part of Japan was 0.73%. None were seropositive (0%), when 26 family members of 6 patients with acute myeloid leukemia sero-converted by blood transfusion during the course of the disease.

Adolescent↗