Japanese journal of medical science & biology最新文献

The development of infection seems to be influenced by the characteristics of antigen-presenting cells (APC) in the infection site. Thus, we compared the Semliki Forest virus (SFV)-antigen-presenting capacity of spleen cells, B-cell lymphomas, bone marrow-derived mast cells and nonparenchymal liver cells by measuring the production of lymphokines in SFV-specific T-cell hybridomas. Spleen cells were able to provide the signals needed to stimulate the production of IL-2, IL-4, IL-6 and IFN-gamma, while B lymphomas the signals leading to only IL-2 production. When bone marrow-derived mast cells were used as APC, SFV-specific T-cell hybridomas produced IL-2, IL-4 and IL-6 in the presence of soluble anti-CD3 antibody. However, no lymphokine production was detected when the SFV antigen was used instead of the antibody. Nonparenchymal liver cells containing liver endothelial cells and Kupffer cells have an APC function stimulating the production of IL-2 and IL-6. These findings confirmed that the T-cell hybridomas can be selectively stimulated by different APC to produce different lymphokines, and it would influence the development of the immune-mediated inflammatory response.

The effect of chloramphenicol (CAP) on the intestinal motility of mice was studied. Acute and chronic CAP treatment significantly increased the food transit time. CAP produced concentration-dependent inhibition of motility of the isolated ileum of mice. Prazosin, propranolol, atropine, ouabain and chlorpromazine all failed to modulate or counteract the CAP-induced inhibition of ileal motility. However, naloxone and hexamethonium slightly modified the inhibitory response of CAP. The inhibitory response of CAP was markedly counteracted by cystine, a guanylate cyclase inhibitor. CAP increased the activity of Ca(++)-ATPase in the ileum in all experiments. Our results suggest that the CAP-induced inhibition of the intestinal motility is not mediated through adrenergic, cholinergic and cAMP or through inhibition of the electrogenic pump. Compared to thiamphenicol (TAP), CAP, with a p-NO2 group in its structure, exhibited more pronounced alteration of both intestinal motility and Ca(++)-ATPase activity. We, therefore, suggest that greater inhibition of ileal motility induced by CAP is possibly a p-NO2-cGMP-Ca(++)-ATPase-mediated mechanism.

Baicalein and baicalin are components of Sho-saiko-to (SST), a Chinese medical drug which is claimed to be therapeutically effective in treating HIV-infected patients. Although 20 micrograms/ml of baicalin was not cytotoxic to CEM cells, a cultured T cell line, it proved to be cytotoxic to HIV-infected CEM cells (CEM-HIV) with a higher HIV-releasing capacity and DNA fragmentation was detected within 24 hr of incubation. However, after incubation of CEM-HIV with a lower dose of baicalin (0.1, 0.3 and 2 micrograms/ml) for 24 and 48 hr, the viable cell number increased by about 25% and the p24 release into the medium was 25% lower than that of the control. After further incubation in the presence of the agent for 6 and 9 days, only cells with a lower HIV-releasing capacity survived. Baicalin might selectively induce apoptosis of CEM-HIV cells which have a high virus-releasing capacity, and stimulate proliferation of CEM-HIV which have a relatively lower capacity of HIV-production.

Antibody production in mice after immunization with diphtheria-pertussis-tetanus (DPT) vaccine was investigated. Six lots of the vaccine produced in the same year by six manufacturers in Japan were chosen. Production of IgE antibody specific to either diphtheria or tetanus toxoid varied among vaccine preparations used, although there was no apparent difference in IgG antibody production after immunization. In addition, the level of IgE antibody specific to diphtheria toxoid was correlated with that of IgG1 antibody and inversely with that of IgG2 antibody. These results suggest that each vaccine preparation may induce a distinct pattern of antibody production and, therefore, the type of immune response induced by vaccination may vary among vaccine preparations.

To evaluate seasonal fluctuations of Dermatophagoides species (sp.) in residential houses in Mie Prefecture, Japan, we employed the ELISA inhibition method with rabbit polyclonal antibody to eggs and adult mites. House dust accumulated for seven days in vacuum cleaners was collected from 14 houses of atopic patients every month for one year. The one-week-dust samples weighed from 2.5 to 117 g (mean 35.9 g). The density of Dermatophagoides spp. in the dust samples were 5 to 755 mites per gram (mean 109). During one week, 100 to 20,400 (mean 4,200) mites of Dermatophagoides sp. were collected. Among 142 samples in one year, 50 (35.2%) contained more than 100 mites per gram, which is a critical number for atopic symptoms. From December to February, 12 (34.5%) out of 35 samples contained more than 100 mites per gram. These results suggest that Dermatophagoides sp. have become a year-round allergen in Japan.

A wild poliovirus type 3 was isolated from a throat swab of a patient with upper respiratory symptoms without paralysis in Shiga Prefecture, in 1993. Wild poliovirus has never been isolated in these nine years in Japan. The most recent isolation of wild poliovirus was of type 1 in 1984 from a case of encephalomyelitis in Aichi Prefecture. Antigenic and PCR-restriction fragment length polymorphism analyses revealed that the Shiga strain was non-Sabin origin. Sequence analysis of the VP1 region confirmed that the isolate was a wild poliovirus type 3. Furthermore, this isolate had higher homology to the isolates from North Vietnam than those from Pakistan or Finland, suggesting that the Shiga strain was imported from Asian area. This strain was also shown to be neurovilurent in transgenic mice carrying human poliovirus receptor gene.

The gelatin-particle-agglutination (PA) test for titrating antibodies against diphtheria, pertussis and tetanus toxins was developed and used for assaying 65 sera from healthy children to assess the antitoxin acquisition in relation to the administration of adsorbed diphtheria-purified pertussis-tetanus (DPT) combined vaccine. The antitoxin titers obtained by the PA test and the conventional methods were correlated well; the correlation coefficient of the diphtheria antitoxin titers between the PA test and the cell culture method was 0.908, that of the tetanus antitoxin titers between the PA test and the passive hemagglutination test 0.968, and that of anti-pertussis toxin titers between the PA test and polystyrene-ball ELISA 0.885. The PA test was shown to be useful in both developed and developing countries, since it is simple to perform, sensitive and specific, and the three antitoxins can be titrated by the same procedure.

Seroepizootiological study of hantavirus infection among 393 urban rats (Rattus norvegicus) captured in six regions in Japan during the period from 1990 to 1994 was carried out by the indirect fluorescent antibody (IFA) test and Western blot (WB). Fifteen out of 393 (3.8%) rat sera were antibody-positive by IFA, i.e., Tokyo Port (12.8%, 6/47), Shimizu Port (5.7%, 2/35), Otaru Port (1.5%, 1/65) and Nagoya City (3.6%, 6/167). In two other regions, i.e., Kasai Seaside Park and Haneda Airport, rat sera were antibody-negative. One serum with a lower IFA titer, 1:64, from Otaru Port was confirmed to be antibody-positive by WB, while two sera from Shimizu Port (IFA titer, 1:32 and 1:64) were not. In Nagoya City, one out of four sera (IFA titer, 1:32) and one of two sera (IFA titer, 1:64) were also confirmed to be antibody-positive by WB. Continuous hantavirus infection among rats in Tokyo Port, Shimizu Port and Nagoya City and the existence of hantavirus among rats in Otaru Port were demonstrated.