Zhonghua Minguo wei sheng wu xue za zhi = Chinese journal of microbiology最新文献

A total of 2,750 strains of beta-hemolytic streptococci was isolated from 10, 510 throat swabs collected from school children in the Taipei area. Most of them were classified as group A (61%) and group G (34%), and about 5% belonged to other groups or unclassified strains. 1, 772 strains of beta-hemolytic streptococci isolated from healthy school children, and 69 strains from sick school children were grouped by the Lancefield precipitin test, fluorescent antibody technique and/or bacitracin paper disk method. A satisfactory correlation (over 90%) was obtained by the latter 2 methods, when compared with the results of the Lancefield technique. The occurrance of false negative or false positive was only 1 or 5%, respectively.

Pseudomonas aeruginosa cultured on deoxyribonucleic acid (DNA) media containing Nissan's heart extract or chicken heart extract could produce extracellular deoxyribonuclease, while on other DNA media with heart extracts from cow, pig and mouse could not. Variation in the kind of peptones in the DNA media did not make significant difference in this activity, although some peptones caused cloudiness of the media. P. aeruginosa did not need cation activators of chloride compounds to produce extracellular deoxyribonuclease. On the modified Eiken's DNA medium, gram negative bacilli other than P. aeruginosa and Serratia marcescens, i.e. Klebsiella, Salmonella, Shigella, Escherichia coli and Alcaligenes did not produce deoxyribonuclease. The production of extracellular deoxyribonuclease activity on the modified Eiken's DNA medium can be used as a supporting test for biochemical identification of P. aeruginosa.

The lectin content of some native plants in Taiwan was studied. The majority of the plants possessing lectin belonged to Leguminosae. Five lectins which are readily available were further studied for their hemagglutination titers, specificity, susceptibility to heat and proteolytic enzymes. The lectins of Ricinus communis had hemagglutination titer of 1:512 which was the highest among the five tested. All lectins were heat labile, destroyed by heating at 100 degrees C for 30 min, but resistant to trypsin and pepsin. The resistance was not due to the presence of any inhibitor in the crude extract, but possibly due to the special configuration of the lectin molecule or other unknow reasons. Among the five lectins only the lectin of Phaseolus vulgaris could not be inhibited by any of the carbohydrates tested. It seems that the lectin of Phaseolus vulgaris is nonspecific, or not specific for ABO blood group, or specific for other blood groups. The inhibiting activity of carbohydrates seems to be specific. The configuration of carbohydrates at carbon atom 2 and/or 4, the type of linkage (alpha or beta), or the carbon number where the linkage is formed seem to be important to the potency of carbohydrates to inhibit the activity of lectin.

The rabbit human thymocyte serum had a selective cytotoxicity on human T lymphocytes. In the presence of guinea pig complement, 23.8% of the otal blood leukocytes were killed by the heterologus antiserum and only 4.2 % were killed by normal rabbit serum. On average 28.2% of the leukocyte preparation obtained by dextran sedmentation were lymphocytes. According to the above figures, 72.3% of the circulating lymphocytes were identified as T cells. The data were comparable to those obtained from other conventional methods used in laboratory animals. The cytotoxicity test was found to be a reliable technique for identifying human T lymphocytes.

This study was undertaken to clarify the natural history and pathogenesis of trachoma. A group of families who live in a formerly trachoma hyperendemic area of Southern Taiwan were placed under continuous surveillance. The development in recent years of the micro immunofluorescence test for trachoma antibody, along with improved cell culture isolation methods, have allowed this surveillance to include repeated effective laboratory studies in addition to clinical observations. After four years' study of one group of families and three years of another, a number of interesting findings have been obtained. Evidence is presented supporting our hypothesis that trachoma is a disease of immumopathology and results from repeated reinfections with the trachoma organisms. The clinical findings of papillae, especially those of an acute nature, has been the clinical finding most closely associated with the isolation of the organism and the demonstration of antibody. Evidence is presented that transmission of the organism is usually within the family group. Although only trachoma immunotypes B and C previously had been associated with trachoma infection on Taiwan, data is presented from one family in which type D infections occurred. While a series of new and reinfections with trachoma organisms were demonstrated in some of the families under observation, the majority of the families not only showed no new infections but showed spontaneous healing or disappearance of clinical and laboratory evidence of trachoma infection. This tendency of active trachoma infection to disappear from a family in the absence of transmission of the organism parallels the rapid fall and prevalence of active trachoma on Taiwan during the past decade.

Excellent in vitro inhibition of measles virus infectivity by ribavirin was detectable by a tube method allowing prolonged maintenance which makes possible the evaluation of efficiency at daily intervals. Optimal efficiency occurred on day 5 to 7, depending on the drug dose. Although syntheses of cellular RNA and protein were inhibited by low drug dosage, the de novo DNA synthesis was enhanced. Peak 4-fold enhancement resulted with 320 mug/ml after 2 days treatment.

From September 1972 to May 1973, 285 raw milk samples and 25 samples of high temperature treated retail milk were examined for Escherichia coli. High temperature treated mild was negative but from raw milk samples 320 strains of E. coli were isolated, among which 25 were enteropathogenic. Using Poly A, Poly B and nonovalent antisera whose pathogenic strains were classified into 6 serotypes: 0-26, 0-55, 0-119,0-125, 0-126 ad 0-128. About half (12) of them belonged to 0-119. Three pathogenic E. coli were sensitive to all of the 8 antibiotics tested while others were resistant to 1-3 antibiotics. Among the 295 nonpathogenic strains, 115 were sensitive to all antibiotics whereas the rest were resistant to 1-5 kinds of antibiotics.

Sera collected from patients with nasopharyngeal carcinoma (NPC, 321 cases), cancer of the other sites (297 cases), diseases of the ear, nose and throat (64 cases) and neighborhood controls matched for age and sex (817 cases) were titrated for antibodies to Epstein-Barr virus (EBV) by the indirect immunofluorescence antibody technique. High anti-EBV antibody titers (greater than or equal to 1:640) were noted in 55% in patients with NPC but only less than 31% were noted for the other 3 groups. The differences in the distributions of anti-EBV antibodies are statistically significant. The geometric mean levels of the antibody titers were 1:342 for the patients with NPC but less than 1:178 for the other 3 control groups. The relative risks shows that more than 40 times higher risk for those with equal to or higher than 1:640 antibody titers than those with lower than 1:40. The patients with NPC also show for higher ridit scales than the other 3 groups. The etiology of NPC was discussed with our findings.

From 1968 to 1973, 793 cases of nasopharyngeal malignancies in Japan were examined histopathologically and immunologically. The majority of the carcinomas were undifferentiated squamous cell carcinomas, including transitional cell carcinoma and lymphoepithelioma. These findings correspond well with those of other countries. There were more well differentiated carcinomas in the old than in the young age groups. The positive rate (80%) and the geometric mean of the anti-VCA-antibody titers (more than 1:750) were remarkably high in the lymphoepithelioma group. These two factors seem to be very important to the study of oncogenesis of nasopharyngeal carcinoma (NPC). The relationship between subpopulations of peripheral lymphocytes in NPC and histopathological classification was investigated. The lymphoepithelioma group had a higher proportion of B cells (complement receptor cells) to T cells (erythrocyte rosette forming cells) than healthy persons throughout the clinical course, and its prognosis was not good.