[Preliminary screening for antiviral AIDS drugs. IV. Report on fiscal year 1992].

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 191 samples tested, seven were found to inhibit the growth of HIV in vitro. Four of seven have hopeful signs, as the ranges of effective doses of the samples are wide.

[Epidemiological study on Chlamydia trachomatis infection in obstetrics and gynecology field in Tokyo].

In conjunction with the Tokyo Branch of Japan Association for Maternal Welfare, we have been carrying out examinations of Chlamydial infection on women, especially pregnant women, living in Tokyo. Specimens were collected from 212 gyneco-obstetric clinics in Tokyo during 4 years from January 1987-December 1990. A total of 13,925 swab specimens from patients who were suspected of sexually transmitted diseases from clinical findings and pregnant women who requested the examination were tested for the presence of antigen to C. trachomatis with EIA (Chlamydiazyme). Epidemiological analysis based on the results and case cards that were described sex, age, occupation and clinical findings were conducted. The results obtained are briefly summarized as follows. 1) C. trachomatis antigen was detected in 12.8% (1,237/9,657) of the female patients, 31.0% (124/400) of the male patients and 6.8% (10/168) of the infants. The detection rates of C. trachomatis antigen in the male patients was significantly higher than that in the female and the infants patients. C. trachomatis antigen was detected in 6.1% (226/3,683) of pregnant women. 2) The detection rates of C. trachomatis antigen were compared by occupation of female patients. Most high rate was 26.6% (53/199) in bar hostess , subsequently 20.1% (102/508) in students, 19.8% (59/298) in prostitutes, 13.6% (455/3,348) in office girls and 7.2% (471/6,573) in house-wives. It was noteworthy that the detection rates of C. trachomatis antigen in students was as similarly high as that in prostitutes. 3) The detection rates of C. trachomatis antigen was also compared by age groups. The detection rate had a tendency to be high in younger people.(ABSTRACT TRUNCATED AT 250 WORDS)

[Usefulness of the mailed specimens for mass examination of Chlamydia trachomatis and Neisseria gonorrhoeae with EIA].

The infections with C. trachomatis and N. gonorrhoeae have recently been determined routinely with the commercial kits for detecting the antigens of these organisms in both the clinical and mass examination laboratories. In mass examination, a change during transporting the specimens must be avoided. Hence, a study on whether the antigens were changed with atmospheric temperature was carried out. As for C. trachomatis, no change in antigen was found on the enzyme immunoassay (EIA) absorbance of the antigen quantity corresponding to the cell of 4.8 x 10(4), 2.4 x 10(4) and 6.0 x 10(3) (IFU/ml) until 5 days at 4, 25 and 37 degrees C respectively after sampling. The coefficient variation was found out to be ca. 10%. In a test on antigen stability of N. gonorrhoeae, similar results to that of C. trachomatis were obtained on the following antigen quantity: 2.4 x 10(3), 3.3 x 10(2) and 9.0 x 10 (CFU/ml) under the same conditions as in the above. The coefficient variation was found out to be 10% or less. To investigate whether there is any difference on the stability of C. trachomatis antigen between mailing and hand carrying, a total of 133 specimens collected from many clinics were subjected to the detection of antigen with the commercial EIA kits. The results of comparison on both transport methods were as follows: agreement rate 96.2%, positive rate 100% and negative rate 95.2%. The highly correlation between the both transportation was confirmed in the detection of antigen; that is, Y = 1.03X + 0.03, r = 0.936.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of small round structured virus infections in acute gastroenteritis outbreaks in Tokyo.

During the three-year period from 1984 to 1987, 506 acute gastroenteritis outbreaks involving 14,383 patients were reported to the Bureau of Public Health, Tokyo Metropolitan Government. Eighty (4,324 patients) of 150 outbreaks (4,860 patients) from which etiologic agents were not identified were subjected to virological investigation. Spherical particles of 28-32 nm in diameter with capsomere-like structures on the surface were detected in patients' stool specimens. Buoyant density of the particles appeared to be 1.36 to 1.40 g/ml in CsCl. Seroconversion to the particles was observed in patients by immune electron microscopy. From these observations, we concluded that the detected particles were members of small round structured virus (SRSV), and that they were implicated in the etiologically ill-defined outbreaks encountered. Prevalence of SRSV infections in these outbreaks was examined by electron microscopy. SRSV was positive in 83.8% of the outbreaks, and 96.4% of the cases. SRSV-positive outbreaks usually occurred during winter in contrast to bacterial outbreaks which often occurred in the summer season. Of 80 outbreaks examined, 53 were associated with the ingestion of oysters, and the remaining 27 mostly with food other than oysters. Oyster-associated outbreaks usually occurred on a small scale, while unassociated ones on diverse scales ranged from family clusters to large outbreaks.

Improved reversed passive hemagglutination for simple and rapid detection of staphycococcal enterotoxins A approximately E in food.

Detection and identification of staphylococcal enterotoxins in food or culture filtrates were performed using the reversed passive hemagglutination (RPHA) technique, with formalized sheep red blood cells (FSRBC) sensitized with immunologlobulins of anti-A, B, C, D, and E rabbit hyperimmune sera fractionated by affinity chromatography. The FSRBC sensitized with anti-A approximately E immunoglobulins showed a high level of reactivity and specificity in RPHA, against homologous types of purified enterotoxins and culture filtrates of toxin-producing strains. No non-specific reactions with various ingredients in foods nor cross-reactions among enterotoxin types were observed. The minimum amount of enterotoxins in foods detected by RPHA was calculated to be 0.01 micorgram/g without concentration, and the recovery rate of experimentally added toxins was calculated to be about 80%. Under routine laboratory practice, detection and identification of enterotoxins from incriminated foods of five food poisoning outbreaks were performed by RPHA within 3 hr after reception of the specimens. Among them, three were determined to be enterotoxin A food poisoning, one to be toxin C and the rest to be intoxication of A and D. The concentrations of the toxins was between 0.014 and 3.65 microgram per gram of food.

Heterogeneity of staphylococcal enterotoxin A on isoelectric focusing and disc electrophoresis.

Heterogeneity of purified staphylococcal enterotoxin A, obtained from a culture supernatant of Staphylococcus aureus, strain 13N-2909, was demonstrated by isoelectric focusing. The toxin was composed of three immunologically identical fractions with isoelectric points of 6.5, 7.0 and approximately 8.0. Heterogeneity of the toxin was also shown by disc electrophoresis. At pH 8.0 and 9.4 two major bands and a faint minor band were observed, while at pH 4.3 only one band was observed. The faster-moving band for the anode in disc electrophoresis at pH 9.4 was found to correspond with the pI 6.5 component from isoelectric focusing, while the slower-moving band corresponded with the pI 7.0 component. From the results of the electrophoretic migration tests of the toxin, the components corresponding to the two major bands found in disc electrophoresis at pH 9.4 were considered to be charge isomers.