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A total of 40 strains of Orientia tsutsugamushi (34 isolates from patients and trombiculid mites in Japan, and 6 prototype strains of antigenic variants) were examined for classification based on the reactivities with type-specific monoclonal antibodies in indirect immunofluorescence tests, and on the restriction fragment length polymorphism of a polymerase chain reaction (PCR)-amplified 56-kilodalton type-specific antigenic protein gene. By these methods, several antigenic and genotypic variants were found among the strains, and these variants were classified into types and further into subtypes. These results suggest that there are many variants in O. tsutsugamushi, and the methods used here seem to be useful for the systematic classification of the numerous variants. A strain which may be a new type distinguishable from those identified previously was also found in this study. Furthermore, variety in the degree of pathogenicity in mice related to type and/or subtype classification were observed.

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The authors previously reported that an extract from Zingiber officinale, traditionally eaten along with raw fish and used in traditional Chinese medicine, effectively destroyed Anisakis larvae in vitro. In this study, we analyzed the effective components of ginger rhizomes. Methanol extracts were fractionated after first being treated with HCl at pH 3, then with NaHCO3 at pH 10, and, finally, with NaOH at pH 13 (fraction 1). In general, this fraction is rich in neutral substances. [6]-Shogaol and [6]-gingerol, known neutral components of ginger rhizomes, were detected using gas chromatography and were found to be the most prevalent components in the fraction, occurring in quantities that resulted in a dose-dependent killing efficacy. Authentic [6]-shogaol and [6]-gingerol could kill Anisakis larvae at a minimal effective dose of 62.5 and 250 micrograms/ml, respectively. However, the concentration of [6]-gingerol in fraction 1 was greater than 20 times that of [6]-shogaol, making the former the most active component in the fraction. Furthermore, synergistic effects between [6]-gingerol and a small amount of [6]-shogaol were observed. Pyrantel pamoate, an available antinematodal drug, had no lethal effect, even at a concentration of 1 mg/ml. In saline solution containing [6]-shogaol (62.5 micrograms/ml), greater than 90% of larvae lost spontaneous movement within 4 h and were destroyed completely within 16 h. Microscopical examinations showed destruction of the digestive tract and disturbances of culticulae.

The transnasal administration of an extract of the parasite Ascaris suum (Asc) to C57BL/6 mice for 3 wk produced marked eosinophilia in the bronchoalveolar lavage (BAL) fluid. This pulmonary eosinophilia was not accompanied by blood eosinophilia. The oral administration of cyclosporin, 50 mg/kg body weight, every other day significantly suppressed the pulmonary eosinophilia. Athymic C57BL/6-nu/nu mice failed to develop pulmonary eosinophilia. These data indicate that pulmonary eosinophilia caused by this parasite extract is T-cell-dependent. Genetically mast-cell-deficient (WB X C57BL/6)F1-W/WV (W/WV) mice developed marked eosinophilia in the BAL, which shows that mast cells are not necessary in the formation of eosinophilia in BAL in this model. C57BL/6, W/WV, and Balb-C mice that developed eosinophilia in the BAL also showed elevated total IgE levels and IgE titers against Asc in the sera. On the other hand, C57BL/6-nu/nu mice and IgE low-responder SJL mice, which developed little eosinophilia, did not show elevated total IgE levels and IgE titers against Asc in the sera. However, oral administration of cyclosporin, 50 mg/kg, which inhibited eosinophilia in the BAL in C57BL/6 mice, did not significantly inhibit the elevation of total IgE or IgE against Asc in the sera. This indicates that serum IgE production is not required for the formation of eosinophilia.