Somei Kojima

Total and Specific IgE Responses in the Acute and Recovery Phases of Respiratory Infections in Children

Total IgE and specific IgE antibodies to common allergens were determined by the enzyme-linked immunosorbent assay in children with Mycoplasma pneumoniae or respiratory syncytial virus (RSV) infections. The decrease of total IgE from the acute to convalescent phase was observed in 105 of 134 (78.4%) children with M. pneumoniae infection and in 40 of 49 (81.6%) of those with RSV infection. Similarly, many patients showed a decrease of the responses of specific IgE in the convalescent phase of the infections. The results indicated that these infections might alter the production of total IgE and IgE specific to common allergens unrelated to the infectious agents.

Allergic Predisposition Among Infants with Bronchiolitis

Allergic predisposition among infants with bronchiolitis was examined. The number of infants with serum IgE exceeding mean +1 SD was 31/70 (44.3%). The rate of positive radioallergosorbent test (RAST) scores of 1 or more to mites, egg white, or milk was 31/71 (43.7%) and that of scores over 2 was 11/71 (15.5%). Eosinophils and/or mast cells were found in their nasal smears on several occasions. These results indicated that allergic predisposition may be observed among infants with bronchiolitis.

Mycoplasma pneumoniae and other pathogens in the aetiology of lower respiratory tract infections among Japanese children.

The causes of lower respiratory tract infections in 1544 children attending a Japanese hospital over a period of 7 years were investigated. Both cultivation and two serological techniques were used to detect Mycoplasma pneumoniae whereas viral involvement was investigated only by serology. Pathogens were identified in 52% of 1175 patients with pneumonia and 36% of 369 patients without pneumonia. Mycoplasma pneumoniae infection was specifically diagnosed in 414 (26.8%) of the 1544 patients. Respiratory syncytial virus (RSV) was dominant in children up to 2 years of age. By the age of 3 years, M. pneumoniae was equalling it in incidence and became the main pathogen in older groups. It is suggested that M. pneumoniae may be more important in the 3-6 years age group than hitherto suspected. These observations may influence the choice of antibiotics for treating lower respiratory tract infections in childhood.

Angiostrongylus costaricensis: Culture of third-stage larvae to young adults in a defined medium

The third-stage larvae of Angiostrongylus costaricensis were successfully cultured to young adults in a chemically defined medium. The most suitable medium for the development was Waymouths medium among eight defined media examined. Twenty-eight days after cultivation in this medium, 77% of the larvae developed to young adults, although these worms gradually died thereafter. When Waymouths medium was supplemented with mouse red blood cells, these young adult worms continued their development. The mean body lengths of the worms cultivated in Waymouths medium supplemented with RBCs were significantly larger than those of the worms in the medium without RBCs on Days 14 and 21 after cultivation. Addition of RBCs was essential for their further development. At 28 days after cultivation, the maximum body length of the worms was 2.1 mm for males and 3.3 mm for females. Additions of serum, yeast extract lactalbumin hydrolysate, and growth factors to Waymouths medium did not provide any additional benefits for worm development.

Angiostrongylus cantonensis: In vitro cultivation from the first-stage to infective third-stage larvae

The first-stage larvae of Angiostrongylus cantonensis were cultured in various media at 27 degrees C. The most suitable medium for the development was Chernins balanced salt solution supplemented with 10% L-15, 10% tryptose phosphate broth, 20% fetal calf serum, and 26 mM sodium bicarbonate. Addition of sodium bicarbonate to the medium facilitated early development of the first-stage larvae. When the first-stage larvae were cultured in the medium under 5% CO2 in air, the worms developed gradually to become quiescent and showed the C shape. Thereafter, the larvae developed to the second stage, retaining their first sheath. About 23 days later, the larvae began to develop to the third stage, being enclosed within the sheaths of the first and second molts. Under these conditions, the larvae developed uniformly and 82% of the larvae reached the third stage 50 days later. About 70% of the third-stage larvae discarded their two sheaths, showing almost the same size as those obtained in vivo. When these exsheathed larvae were inoculated into rats, they developed into adult worms and deposited numerous first-stage larvae.

A mouse monoclonal antibody that binds to an α-stichocyte of Trichinella spiralis

Monoclonal antibodies were generated for the isolation of specific antigens from Trichinella spiralis. A monoclonal antibody (TS32D12) of the Igg1 class was selected according to its reactivity and specificity by enzyme-linked immunosorbent assay and immunofluorescent technique. The TS32D12 antibody was purified from ascites by fast protein liquid chromatography. The purified antibody showed a sensitive reaction to the T. spiralis antigen, but not to any other heterologous parasite antigens so far examined. Western blot analysis showed that the monoclonal antibody bound to epitopes present on the 160-kDa molecule. The antigen molecule was fragmented into 56-kDa molecules by heat treatment. The epitopes seemed to be destroyed since the antibody could not bind to the 56-kDa molecule. Staining with the periodic acid-Schiff (PAS) reagent suggested that the two molecules of 160 kDa and 56 kDa were glycoproteins. The 160-kDa molecule was detected only in the α-stichocyte of T. spiralis muscle larvae.

Production and properties of reaginic antibodies in rabbits infected with Clonorchis sinensis or Schistosoma japonicum

Abstract The production of reaginic antibodies detected by homologous passive cutaneous anaphylaxis (PCA) was demonstrated in all rabbits experimentally infected with either Clonorchis sinensis or Schistosoma japonicum . The antibodies appeared in the sera as early as 3 weeks after exposure and persisted with relatively high titers for at least 7 weeks in some animals. The antisera of rabbits infected with C. sinensis were found to be cross reactive against heterologous trematode antigens, although PCA titers were less than 3% of the titer by the homologous antigen; no cross reaction was observed between S. japonicum antiserum and the heterologous antigens. PCA activity of the antisera was completely destroyed in some samples by heat treatment at 56 C for 2 hr, but partially in the others even after heating for 6 hr. However, the physicochemical properties of these antibodies were analogous to human IgE; the PCA activity was eluted with 0.035 M phosphate buffer from a DEAE-cellulose column and recovered in the ascending portion of the IgG peak by Sephadex G-200 gel filtration. PCA activity was found in a β region in preparative agar electrophoresis.

Paragonimus westermani: A comparative study on the migration route of the diploid and triploid types in the final hosts

Recent studies on chromosomes have shown the presence of diploid and triploid types of Paragonimus westermani. To determine any possible biological differences between them, the migration route and development of the diploid type in the final hosts were compared with those of the triploid type. In the cat, the definitive host, larvae of the diploid type migrated to the abdominal wall, remained there for two weeks, and then migrated to the lung. In the rat, the abnormal host, some orally administered metacercariae of the diploid type made cysts in the lung and laid eggs, but the triploid type did not lay any eggs. Neither type of P. westermani migrated to the liver of the rat, in contrast to the previously reported fact that P. miyazakii and P. ohirai migrate to the liver and develop there. From these results, it seems likely that the two types of P. westermani are closely related.

Induction of resistance in Oncomelania hupensis nosophora against Schistosoma japonicum, but not against Paragonimus ohirai, using irradiated miracidia

Oncomelania hupensis nosophora snails sensitized with X-irradiated Schistosoma japonicum miracidia demonstrated resistance against a following challenge infection with non-irradiated homologous miracidia. The resistance in O. h. nosophora against S. japonicum was acquired within 1 day of sensitization, and it was strongest in a group challenged at an interval of 3 days. The resistance persisted for at least 4 weeks. Histological examinations revealed amoebocyte accumulation around the challenged S. japonicum sporocysts. On the other hand, when O. h. nosophora sensitized by exposure to X-irradiated P. ohirai or S. japonicum miracidia were subsequently challenged with normal P. ohirai miracidia, no resistance was observed, although they expressed the resistance against heterologous S. japonicum infection.

Schistosoma japonicum and Paragonimus ohirai: antagonism between S. japonicum and P. ohirai in Oncomelania nosophora

Antagonistic interactions between Schistosoma japonicum and Paragonimus ohirai were examined in the snail host, Oncomelania nosophora. When P. ohirai-infected snails were exposed to S. japonicum miracidia at intervals of 4 to 18 weeks post-first exposure, only a few snails (0-7%) were found to be superinfected with S. japonicum sporocysts. Sporocysts were fewer in number than those of single infected controls. Mature S. japonicum cercariae were not observed. Furthermore, when the snails were examined at intervals of 14 to 18 weeks post-second exposure, neither sporocysts nor cercariae of S. japonicum were found. On the other hand, when the snails were exposed to miracidia of S. japonicum and P. ohirai simultaneously, they were easily infected with both parasites. At 26 weeks after simultaneous exposure, however, the infection rate of S. japonicum was significantly lower than that of controls. In contrast, when S. japonicum-infected snails were exposed to P. ohirai miracidia, they were superinfected with P. ohirai, although the infection rate was somewhat lower than that of controls. These results indicate the existence of antagonism between S. japonicum and P. ohirai in O. nosophora. Furthermore, P. ohirai was dominant over S. japonicum in the antagonistic interactions in this snail host.