Shiro Kasuya

Lethal efficacy of extract from Zingiber officinale (traditional Chinese medicine) or [6]-shogaol and [6]-gingerol in Anisakis larvae in vitro.

The authors previously reported that an extract fromZingiber officinale, traditionally eaten along with raw fish and used in traditional Chinese medicine, effectively destroyedAnisakis 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 killAnisakis larvae at a minimal effective dose of 62.5 and 250 μg/ml, respectively. However, the concentration of [6]-gingerol in fraction 1 was >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 μg/ml), >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 cuticulae.

Demonstration of Antigenic and Genotypic Variation in Orientia tsutsugamushi Which Were Isolated in Japan, and Their Classification into Type and Subtype

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.

T-Cell-Dependent Accumulation of Eosinophils in the Lung and Its Inhibition by Monoclonal Anti-Interleukin-5

The transnasal administration of an extract of the parasite Ascaris suum to C57BL/6 mice for 3 weeks produced marked eosinophilia in the bronchoalveolar lavage (BAL) fluid. The oral administration of ciclosporin significantly suppressed the pulmonary eosinophilia. Athymic C57BL/6-nu/nu mice failed to develop pulmonary eosinophilia. These data indicate that the 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 lung eosinophilia in this model. Monoclonal antimurine interleukin-5 injected intraperitoneally clearly inhibited the infiltration of eosinophils in the lung, suggesting that T-cell-derived interleukin-5 is essential.

How effective is the agar plate method for Strongyloides stercoralis

The sensitivity of the agar plate method for the diagnosis of Strongyloides stercoralis was studied experimentally. Results demonstrated that this method was sensitive enough to detect S. stercoralis even when only a few worms were present.

Influence of an estuary dam on the dynamics of bisphenol A and alkylphenols

The present study investigated the dynamics of xenoestrogenic compounds, bisphenol A (BPA) and alkylphenols, in the Nagara River, which has an estuary dam. The results were compared with the neighbouring Ibi River, which does not have such a dam. The mean concentrations of BPA in the Nagara River ranged from 0.06 to 0.33 microg/L compared with 0.25 microg/L in the Ibi River. Although these results are similar to those for rivers in urban areas, the concentrations in the bottom water layer (up to 15 cm from sediment surface) in the Nagara River were significantly higher, with a maximum magnification (bottom water layer/surface water) of more than 650. The main portions of BPA in the bottom water layer in the Nagara River were in a soluble state. Moreover, there was a high correlation (R(2)=0.78) between the BPA content in the bottom sediment and BPA concentration in the bottom water layer. BPA and 4-nonylphenol (4NP) content was higher in the Nagara River sediment than in the Ibi River sediment. However, there was no discrepancy between 4NP concentrations in the surface water and the bottom water layer. These phenolic compounds were highly protected from aerobic degradation in the bottom sediment in the reservoir of the dam and the observed discrepancy depended on the differences in solubility of the compounds. The results show that an estuary dam facilitates accumulation and storage of xenoestrogenic compounds.

Reduced fecundity of Hymenolepis nana due to thymus-dependent immunological responses in mice

Abstract Reduced fecundity of Hymenolepis nana due to thymus-dependent immunological responses in mice. International Journal for Parasitology 16 : 81–85. The fecundity of the dwarf tapeworm, Hymenolepis nana , was enhanced in congenitally athymic nude CD-1 (ICR) mice but depressed to the same degree as in phenotypically normal littermates when they were reconstituted with thymocytes before infection. The reduction in fecundity of this parasite was clear only when H. nana were recovered from those strains of mice which demonstrate a “late response” against luminal cysticercoid challenge before the established worms become fully mature (within 15 days of initial immunizing egg inoculation). The fecundity of H. nana in dd mice, which acquire the late response within 30–40 days, was greatly advanced than that in BALB/c or CD-1 (ICR) mice and somewhat better than even that in the nude CD-1 (ICR) mice and appeared to be little, or not at all, depressed. The fecundity and longevity of this parasite, highly variable among mouse strains, is discussed in terms of variations in the rapidity of expression of protective immunity against the lumen phase.

Kinetics and collagenolytic role of eosinophils in chronic gastric ulcer in the rat

Abstract An association between eosinophils and tissue damage has been observed in numerous disorders. However, few reports have addressed the role of infiltrating eosinophils in gastric ulcer healing. The aim of this study was to investigate the kinetics and role of eosinophils infiltrating experimental chronic gastric ulcers in the rat. We developed a monoclonal antibody against human matrix metalloproteinase 1 (MMP1) purified from conditioned culture medium of human skin fibroblasts. Acetic acid-induced gastric ulcers were resected from rats on days 1, 3, 5, 10, 20, 40, and 180 after the days of induction (day 0). Tissue specimens were immunostained with this antibody and examined with an electron microscope. Few eosinophils were observed in the granulation tissue until day 20. By days 40 and 180, MMP1-positive eosinophils had increased in the granulation tissue of open ulcers. Azan staining revealed dispersed collagen fibers around infiltrating eosinophils. In contrast, scars demonstrated few eosinophils in fibrous tissue on days 40 and 180. Eosinophils which express MMP1 infiltrate granulation tissue at the chronic stage of gastric ulceration. The results suggest that eosinophils may play a role in tissue remodeling and deterioration of ulceration.

Virulence in Mice of Orientia tsutsugamushi Isolated from Patients in a New Endemic Area in Japan

Four strains of Orientia tsutsugamushi (KN‐1, KN‐2, KN‐3 and GJ‐1) isolated from patients in an area of Gifu Prefecture, Japan, in which tsutsugamushi disease is newly endemic, were examined for their virulence in mice. Among these, KN‐1 (identified as Kawasaki type), GJ‐1 (identified as Kuroki type) and KN‐2 strains were found to be non‐lethal for BALB/c mice as well as CH3/HeJ mice, even with high doses (106 × being the 50% mouse infectious dose). On the other hand, the KN‐3 strain was found to be sufficiently virulent to kill BALB/c mice. Among the prototype strains (Gilliam, Karp and Kato), the Karp and Kato strains exhibited high virulence to mice, while the Gilliam strain killed only a susceptible strain of mouse. BALB/c mice infected with KN‐1 and KN‐2 strains showed significant splenomegaly and moderate ascites accumulation in the first week of infection, while these symptoms became prominent during the second week of infection using KN‐3, Karp and Kato strains. After infection with the GJ‐1 strain, these symptoms were not observed. Antibody responses induced by infections with highly virulent strains were lower than that with low or intermediate virulent strains.

Identification of Closely Related Hydrobaenus Species (Diptera: Chironomidae) Using the Second Internal Transcribed Spacer (ITS2) Region of Ribosomal DNA

Three species of Japanese Hydrobaenus Fries (H. Kondoi, H. biwaquartus and H. kisosecundus) can be separated by variation in the sequence of the second internal transcribed spacer (ITS2) regions of ribosomal DNA. Suggested synonymy of H. kondoi with H. biwaquartus is refuted, and previously suggested diagnostic morphology (virga length, antennal, leg and venarum ratios, shape of tergite IX and gonostylus length) distinguishes the taxa. No difference in larval morphology was found. H. kisosecundus is readily distinguished on adult and larval morphology from H. kondoi and H. biwaquartus, and is more distant by molecular similarity measures. ITS2 regions apparently provide useful information for distinguishing closely related species in Chironomidae.

Correlation between protective antibody response and patent infection with Hymenolepis nana in mice

Abstract Correlation between protective antibody response and patent infection with Hymenolepis nana in mice. International Journal for Parasitology16: 197–203. Mice inoculated with mouse-derived cysticercoids of Hymenolepis nana, as well as with eggs, produced IgG and IgE antibodies that were detected by double diffusion (DD) and passive cutaneous anaphylaxis (PCA), respectively. When mice inoculated with eggs (day 0) were challenged with eggs (day 66), all were resistant to the challenge (assessed by the failure of cysticercoid recovery in the intestinal tissue) and produced protective antibodies evidenced by passive transfer, as well as IgG and IgE isotypes. When mice inoculated with eggs (day 0) were treated with a highly efficacious cestocide, praziquantel on day 6 at the beginning of the lumen phase, all were also resistant to the egg challenge on day 66, however, IgE, IgG, and protective antibodies were not detected. When mice treated with praziquantel before patent infection were repeatedly challenged with high doses of eggs, some of them produced IgG and IgE antibodies. From these results, it is suggested that (1) the production of protective antibody is a secondary response after patency (which may be ascribed to eggs released from mature worms), and (2) mice initially given eggs are highly resistant to egg challenge showing that an effector mechanism of acquired resistance to egg challenge may be expressed without high titres of protective antibody, at least in the serum.