A survey of rotavirus infection in the topics.

The age distribution of rotavirus antibody in the serum of inhabitants of Laos and Indonesia was studied by the neutralization test using antigenically related calf rotavirus (NCDV) as a substitute for non-cultivable human rotavirus. The results revealed that both the rate of antibody-positives and the modal titers of antibody distribution by each age group in these countries were higher than those in respective are groups of Japanese, which suggest higher endemicity of rotavirus infection in these countries. A survey of rotavirus in diarrheic patients' stools by enzyme-linked immunosorbent assay indicated that the virus infection occurred most frequently among infants between 4 and 12 months of age.

Immune responses in rabbits treated with tetracycline.

Cellular and humoral immunological phenomena in rabbits treated with tetracycline were investigated by lymphocyte transformation, leucocyte migration inhibition, and indirect hemagglutination tests. Cellular and/or humoral immunity against tetracycline and/or homologous or autologous rabbit gamma globulin was acquired by about two-thirds of the rabbits, with some also acquiring immunity against homologous tissue antigen after prolonged tetracycline administration. Based on these results, the significance of immune responses to autoantigens by drug administration was discussed in relation to potential agents for the induction of autoimmune diseases.

Geographic distribution of arbovirus antibodies in indigenous human populations in the Indo-Australian archipelago.

Sera from lifetime residents in 16 localities of the Indo-Australian archipelago and adjacent areas were tested for hemagglutination-inhibition antibody against four alpha-viruses (Sindbis, Getah, chikungunya, and Ross River) and for neutralizing antibody against six flaviviruses (dengue 2 and 3, Japanese encephalitis, Murray Valley encephalitis, Kunjin, and Edge Hill). Mosquito collections were carried out in some of the localities to study vector relationships to distribution of the arbovirus antibodies. Antibodies specific to Sindbis and Getah viruses were rare except in north Australia. Chikungunya virus-specific antibody was highly prevalent in localities of the Oriental zoogeographic region and Wallacea, rare in west New Guinea, and absent in north Australia. Age distribution of chikungunya antibody suggested that the antibody last occurred in most Indonesian localities about 30 years ago. Ross River virus-specific antibody was confined to localities of the Australian zoogeographic region. Antibodies reacting to dengue 2 and 3 viruses occurred in high frequency in the entire area of the archipelago. Antibodies specific to Murray Valley encephalitis and Kunjin viruses were also widespread although at a very low frequency. Japanese encephalitis virus-specific antibody was highly prevalent in areas west of Wallace's Line while it was absent in areas east of the line with the exception of Lombok. Antibody to Edge Hill virus was rare and confined to the Australian zoogeographic region. The distribution of arthropod vectors, vertebrate hosts, and of arboviruses are discussed in relation to zoogeographic divisions.

Demonstration of antibody activity to clioquinol in sera of experimental rabbits and patients with subacute myelo-optico-neuropathy.

Antibody to clioquinol(5-chloro-7-iodo-8-hydroxyquinoline:CIHQ) was detected by passive hemagglutinating reaction in rabbits receiving a prolonged administration of Emaform which was once a commercial preparation of CIHQ. The antibody was shown to be in the immunoglobulin fractions by separation with a specific immunoadsorbent, and it had relatively broad antigenic specificity. The antibody was also demonstrated in sera from patients who suffered from Subacute Myelo-Optico-Neuropathy (SMON) and from normal healthy individuals. However, its titer and frequency of positive reactors in the former were higher than those in the latter, and the two groups could be differentiated each other in frequency distribution patterns of the antibody proprietors. From these results, we discussed on desirable application of sero-epidemiological study to assessment of effects of chemical pollutants on living systems.

Increased absorption of iodochlorhydroxyquin by rat intestine in the presence of solubilizing agents.

The intestinal absorption of iodochlorhydroxyquin (clioquinol) by the rat was studied by determining the radioactivity in the bile, blood and several organs 90 min after direct application of 125I-labeled clioquinol into the duodenum. The addition of solubilizing agents such as carboxymethyl-cellulose and lauryl sulfate to clioquinol preparation markedly enhanced the intestinal absorption of the drug in either the presence of absence of bile secretion which, by itself, increased the drug absorption. Possible significance of the enhanced absorption of clioquinol by solubilizing agents in the etiology of subacute myelo-optic neuropathy (SMON) in Japan is discussed.

Sero-epidemiological study on equine influenza in Japan.

A serological survey was conducted on horse sera collected for 7 years just before the first outbreak of equine influenza (EI) infection in Japan in 1971. No antibodies against the A/Equi-1/Prague/56 (equi-1) and A/Equi-2/Miami/63 (equi-2) strains of EI virus were detected in any of the sera of 452 native horses when employing hemagglutination inhibition (HI) and complement fixation (CF) tests against viral (V) antigen. On the contrary, of the 80 imported horses, 48 (60.0%) had HI titers of 1:8 or higher against equi-1 and 23 (28.8%) against equi-2. In the CF-V test 42.6% of the horses showed titers of 1:4 or higher against equi-1 antigen and 42.9% against equi-2 antigen. However, all the test sera of the native and imported horses were negative (less than 1:4) in CF tests against soluble human influenza antigen. Epidemiological analysis was carried out to clarify the relationship between the history and the presence of serum antibody against EI viruses in individual imported horses.

Further studies of specificity of antibodies contained in antiserum against poliovirus.

Antigenic components of Mahoney strain (poliovirus type 1) involved in virus neutralization reaction were analyzed with mutant Mahoney strains resistant to inhibitors in equine serum (inhibitor-resistant mutants) by means of the kinetic neutralization test. It was shown that absorption of anti-Mahoney serum with five inhibitor-resistant mutants yielded sera with different antibodies, of which three had distinct specificities and two specificities possibly partly related to one of those three sera. Further, it was found that step wise selection of Mahoney variants resistant to one, two, three and four different inhibitors resulted in gradual deviation of its antigenic composition from that of the original strain. From these results, the possible presence of three or more distinct antigenic determinant sites on the surface of Mahoney strain was indicated.