We studied the effect of slime protease isolated from Staphylococcus epidermidis on the production of interleukin-3(IL-3) and macrophage activating factor (MAF) by T lymphocytes. The production of IL-3 by mouse spleen lymphocytes was suppressed dose-dependently by treatment with S. epidermidis slime protease (25,50 and 100μg/ml). Namely, the incorporation of ³H-thymidine into mouse myeloblasts decreased. The production of MAF was also suppressed dose-dependently. We observed that the glucose content remaining in the culture medium increased after treatment with S. epidermidis slime protease.

These results suggest that S. epidermidis slime protease which inhibits the production of lymphokines by T lymphocytes, is one of the serious pathogenic factors.

Groups C and G streptococci were investigated using, β-hemolytic streptococci isolated from various clinical specimens at 7 medical institutions in Iwate during the past 11 years from 1979 to 1989. In order to analyze the characteristic trends of the isolates, we investigated the sources of clinical specimens, isolation rates by sex and ages of patients, and the species. All isolates were serologically grouped, and their species biochemically identified. The minimum inhibitory concentrations (MIC) of penicillin (PCG), ampicillin (ABPC), cephaloridine (CER), cephalexin (CEX), tetracycline (TC), chloramphenicol (CP), erythromycin (EM), oleandomycin (OL) and lincomycin (LCM) were determined. Forty-five group C streptococci and 385 group G streptococci were isolated mostly from throat swabs and partly from sputum, otorrhea, pus, vaginal discharge, urine and stool specimens. Groups C and G streptococci were isolated most frequerltly from children aged 5~14; 24 (53.3%) of 45 strains of group C streptococci and 344 (89.4%) of 385 strains of group G streptococci. The isolation rate of group C streptococci from males was higher than that from females with a ratio of 32:13, and the isolation rate of group G streptococci from males was also higher than that from females with a ratio of 241:144. Of the 45 group C streptococci, 2 were identified biochemically as Streptcoccus equi subsp. equi, 4 as Streptcoccus equi subsp. zooepidemicus, 35 as Streptcoccus dysgalactiae and 4 as Streptcoccus anginosus. Of the 385 group G streptococci, 343 were identified as S. dysgalactiae, 38 as S. anginosus and 4 as Streptcoccus canis. All the isolates were highly susceptible to PCG, ABPC, CER and CEX. None of the group C streptococci were resistant to TC, but 7 strains of group G streptococci were resistant to TC (MIC≧25μg/ml). These 7 strains consisted of 6 strains of S. dysgalactiae and 1 of S. anginosus, and then the 7 TC-resistant strains were isolated in 1979, 1980, 1983, 1985, 1986, and 1988. Two strains of group C streptococci and 4 strains of group G streptococci were resistant to EM, 2 strains each of group C and G streptococci to OL and 2 strains of group C streptococci and 3 strains of group G streptococci to LCM. The resistant strains to EM, OL, and LCM were all S. dysgalactiae and then these resistant strains to EM, OL and LCM were isolated from 1979 to 1983, and have not been obtained since 1984.

This study was designed to review medical records of 302 patients with periodontal diseases (40~78-years old) and evaluate the frequency and nature of systemic disorders in these patients by age-groups (40~49, 50~59, and 60~78). The results are as follows: In the present conditions, cardiovascular abnormalities are the most prevalent in any age group. In the past history of disease, digestive disorders were most frequent in the age groups in the forties and sixties to seventies, and genitourinary disorders were in the age group of fifties. When the past and present medical conditions were combined, the frequency of cardiovascular and digestive disorders was high in any age group, while that of genitourinary disorders and respiratoly ones were high in the group of fifties, and over sixties respectively. The number/percent of patients with present disease problems increased with age and those free from disease problems, at present as well as in the past, decreased with age. The number/percent of patients affected by more than two systemic disorders, including both the present and past illnesses increased with age.

The purpose of this study is to investigate bacterial contamination of air released from an air compressor used in dental clinics. Seven dental clinics in Morioka were chosen at random. Air released from the compressors installed at these clinics was sampled by blowing against nutrient agar plates for a minute at a distance of about 20 cm away from the outlet of a three way syringe.

After 48-hr culture at 37℃, the number of colonies formed was counted. Water discharged from the compressors was smear-sampled. Bacteria floating in a room containing machines were determined using an RCS air sampler. The existence of bacteria was confirmed in air forced out of the air compressor. Two favorable sources for bacterial growth and reproduction were detected: air exhausted from the vacuum pump, and water collected inside the compressor. This study suggested that air from a vacuum pump should be emitted to the outside atmosphere and the supply of air to the compressor should come from outside the clinic. In addition, water should be frequently discharged from a compressor, and air should be cleared from it after daily dental practice in order to keep the inside dry.

Group A streptococci were isolated from throat-swabs once a month from January, 1985 to March, 1990. The subjects were school aged children accommodated in an institution because of weak physical condition or chronic diseases. Serum immunoglobulin M (IgM) and G (lgG) antibodies were measured by an enzyme-linked immunosorbent assay, using group A streptococci (type M-4, M-6 and M-12) as antigens.

The results are summarized as follows:

The highest levels of IgM and IgG antibodies were obtained with antigen concentrations of 0.5 to 1.0μg/ml. The antigens at these levels were type-specific. When M-type antibodies were compared with T-type, the levels of M-type antibodies were eight times as high as those of T-type antibodies in both IgM and IgG M-type antibodies. M-type antibodies continued to exist in children in whom T-type antibodies disappeared. We confirmed the survival of M-type antibodies to be longer than T-type antibodies.