Serological characterization of fibrinogen and its derivatives was attempted by using antibody-coated latex agglutination and counterelectrophoresis. It was found that: 1) fibrinogen was not only capable of agglutinating uncoated latex particles but also fixed to the latex particles; 2) the sensitivity of some of the latex reagents used for the detection of fibrinogen may reflect the antibody activity to the derivatives with altered antigenicity in which FDP-E antigen is more readily available than in intact fibrinogen molecules, as the one contained in Liquid Human Plasma but absent in its batches prepared in the presence of plasmin inhibitors; 3) increase in FDP-E antigenicity was noticed in the course of fibrinogenolysis so its availability would indicate the occurrence and extent of proteolytic process on fibrinogen; and 4) FDP-E-antigen developed in the course of plasmin digestion may not be shared by intact fibrinogen since the former was reactive in counterelecrtophoresis against anti-FDP-E serum even when the latter had been absorbed with fibrinogen.
An attempt was made to reveal the antigenic determinant site of enterovirus (EV) 70 by application of Harman's factor analytics. The normarized neutralization rate constant (NK) values obtained by the kinetic-neutralization tests (NT) with 12 strains of EV70 isolated during the period from 1971 to 1976 were used in the principal factor analysis. From the analytic results, it was suggested that at least two antigenic determinant sites, composing to variable antigenic factor (VAF) and common one (CAF), might be closely related to the antigenic makeup. There were no significant differences in CAF score among the strains, and they were numerically classified into prototype-like and prime-like virus groups from the VAF scores. The drift appeared here could be explained as successive alteration of VAF scores. Chromatographic analyses were carried out on intratypic variable and common particles with two virus strains, i.e. the prototype J 670/71 and prime G-2/74. The intratypic variable and common particles were eluted in low and high ionic concentrations at neutral pH, respectively. It was concluded that the virus populations of two strains were heterogenic in the proportion of variable to common virus particles.
During the period from May to August, 1978, an epidemic of hand, foot and mouth disease (HFMD) occurred in Gifu prefecture. Epidemiological, virological and serological investigations were performed. Cases involved ranged from 0 to 31 years of age, and 80.2% of them were under 5 years of age. The incidence of HFMD with neurological complication (3.7%) was lower than that in 1973. Enterovirus 71 (EV71) was isolated from 83 of 108 cases (75.9%) and a significant rise in the neutralization antibody titer against the isolate was found in 14 of 25 cases (56%) . Thus, it was confirmed that the causative agent of the epidemic of HFMD in Gifu prefecture in 1978 was enterovirus 71.
In convalescent-phase sera of patients with dengue hemorrhagic fever, hemagglutination-inhibiting (HI) antibody of immunoglobulin (Ig) A class, in both monomeric and oligomeric forms, was detected. It was found to be less typespecific than IgM HI, and as broadly cross-reacting as IgG HI antibodies.
Two hundred and eighty-seven drug-resistant strains of Escherichia coli were isolated from 150 ground meat samples of chicken purchased at markets in 1978, and 210 R plasmids were demonstrated in those strains. The most frequent resistance pattern (88%) included SA or TC resistance. The pattern associated with SM resistance was secondly frequent and the frequency of CM resistance was as low as 20%. In relation to TC, CM, SM, and SA, the isolation frequency was the highest with strains triple resistant to any combination of three of four drugs. Among the resistant E coli strains, R plasmids with single resistance to each of four drugs and those accompanying KM or APC resistance were most frequently demonstrated. The use of antibiotics has brought many advantages to the livestock industry. The drugs not only cure the animals of bacterial infections but also accelerate growth and the increase in the body size. However, long-term administration of antibiotics has brought an increase in the number of drug-resistant organisms, especially those with conjugally transferable resistance. This paper deals with the studies on the distribution of drug resistance plasmids among E. coli strains isolated from chickens purchased at commercial markets. We isolated 287 E. coli strains resistant to any one or any combination of the drugs tested, i.e., TC, CM, SM, SA, KM and APC. Drug-resistant E. coli strains were isolated from all chicken materials tested. SA-and TC-resistant strains were isolated most frequently (87.8% and 87.5%, respectively), followed by SM- (68.6%) and KM-resistant ones (41.8%) . The isolation frequencies of CM- and APC-resistant strains were very low, being 22.0% and 22.3%, respectively.