Dexamethasone Downregulates Expressions of 14-3-3ß and γ-Isoforms in Mice with Eosinophilic Meningitis Caused by Angiostrongylus cantonensis Infection.

Steroids are commonly used in patients with eosinophilic meningitis caused by A. cantonensis infections. The mechanism steroids act on eosinophilic meningitis remains unclear. In this mouse experiments, expressions of 14-3-3 isoform ß and γ proteins significantly increased in the CSF 2-3 weeks after the infection, but not increasedin the dexamethasone-treated group. Expression of 14-3-3 ß, γ, ε, and θ isoforms increased in brain meninges over the 3-week period after infection and decreased due to dexamethasone treatment. In conclusion, administration of dexamethasone in mice with eosinophilic meningitis decreased expressions of 14-3-3 isoform proteins in the CSF and in brain meninges.

Comparative studies on the proteomic expression patterns in the third- and fifth-stage larvae of Angiostrongylus cantonensis.

Angiostrongylus cantonensis is an important zoonotic parasite causing eosinophilic meningitis and eosinophilic meningoencephalitis in humans. In this study, the protein expression profiles of the infective third- and pathogenic fifth-stage larvae (L3 and L5) of this parasite were compared by proteomic techniques. Isolated protein samples were separated by two-dimensional gel electrophoresis (2-DE), stained with silver nitrate, and analyzed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Proteins from L5 were mainly at pH 5-7 and with molecular weight (MW) 40-100 kDa, whereas those from L3 were at pH 5-6 and with 5-35 kDa. Of 100 protein spots identified, 33 were from L3 whereas 67 from L5 and 63 had known identities, whereas 37 were hypothetical proteins. There were 15 spots of stress proteins, and HSP60 was the most frequently found heat stress proteins in L5. More binding and protein transport-related proteins were found in L5 including peptidylprolyl isomerase (cyclophilin)-like 2, serum albumin, preproalbumin precursor, and dilute class unconventional myosin. L3 had a higher expression of cytoskeleton and membrane proteins than L5. In addition, four protein spots were identified in the sera of the rat host by Western blot analysis. The present proteomic study revealed different protein expression profiles in L3 and L5 of A. cantonensis. These changes may reflect the development of L3 from the poikilothermic snails to L5 in the homoeothemic rats. This information may be useful for the finding of stage-specific proteins and biomarker for diagnosis of angiostrongyliasis.

Anthelmintic activities of aporphine from Nelumbo nucifera Gaertn. cv. Rosa-plena against Hymenolepis nana.

Nelumbo nucifera Gaertn. cv. Rosa-plena (Nelumbonaceae), commonly known as lotus, is a perennial aquatic plant grown and consumed throughout Asia. All parts of N. nucifera have been used for various medicinal purposes in oriental medicine. From the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena (an aquatic plant), liriodenine (1), lysicamine (2), (-)-anonaine (3), (-)-asimilobine (4), (-)-caaverine (5), (-)-N-methylasimilobine (6), (-)-nuciferine (7), (-)-nornuciferine (8), (-)-roemerine (9), 7-hydroxydehydronuciferine (10) and cepharadione B (11) were isolated and identification and anthelmintic activities of aporphine was evaluated against Anisakis simplex and Hymenolepis nana. This study found that the above constituents killed H. nana or reduced their spontaneous movements (oscillation/peristalsis). However, the above constituents at various concentrations demonstrated no larvicidal effect or ability to halt spontaneous parasite movement for 72 h against A. simplex, respectively. In addition, according to an assay of cestocidal activity against H. nana and nematocidal activity against A. simplex, we found that the above compounds showed greater lethal efficacy on H. nana than against A. simplex. Further investigation showed that these above constituents have effects against peroxyl radicals under cestocidal effect. Together, these findings suggest that these constituents of Nelumbo nucifera Gaertn. cv. Rosa-plena might be used as anthelmintic agents against H. nana.

Antioxidant, anti-adipocyte differentiation, antitumor activity and anthelmintic activities against Anisakis simplex and Hymenolepis nana of yakuchinone A from Alpinia oxyphylla.

BACKGROUND: Alpinia oxyphylla is a common remedy in traditional Chinese medicine. Yakuchinone A is a major constituent of A. oxyphylla and exhibits anti-inflammatory, antitumor, antibacterial, and gastric protective activities. METHODS: Antioxidant and antitumor characteristics of yakuchinone A in skin cancer cells as well as novel mechanisms for the inhibition of adipocyte differentiation, cestocidal activities against Hymenolepis nana adults, and nematocidal activities against Anisakis simplex larvae are investigated. RESULTS: Yakuchinone A presents the ability of the removal of DPPH·and ABTS+ free radicals and inhibition of lipid peroxidation. Yakuchinone A suppresses intracellular lipid accumulation during adipocyte differentiation in 3 T3-L1 cells and the expressions of leptin and peroxisome proliferator-activated receptor γ (PPARγ). Yakuchinone A induces apoptosis and inhibits cell proliferation in skin cancer cells. The inhibition of cell growth by yakuchinone A is more significant for non-melanoma skin cancer (NMSC) cells than for melanoma (A375 and B16) and noncancerous (HaCaT and BNLCL2) cells. Treatment BCC cells with yakuchinone A shows down-regulation of Bcl-2, up-regulation of Bax, and an increase in cleavage poly (ADP-ribose) polymerase (PARP). This suggests that yakuchinone A induces BCC cells apoptosis through the Bcl-2-mediated signaling pathway. The anthelmintic activities of yakuchinone A for A. simplex are better than for H. nana. CONCLUSIONS: In this work, yakuchinone A exhibits antioxidative properties, anti-adipocyte differentiation, antitumor activity, and anthelmintic activities against A. simplex and H. nana.

Effects of age and splenectomy on heavy infection of Angiostrongylus cantonensis in rats.

This study was designed to determine the effects of age and the role of spleen in rats with heavy Angiostrongylus cantonensis infection. Young rats (8 weeks) infected with 100 larvae were found to have significantly higher worm recovery rate (75.0±6.6%) than the adult (6 months) (55.7±1.5%) and the aging ones (13 months) (57.6±4.0%). Moreover, the recovery rate in adult rats with 400 larvae (33.6±10.67%) was significantly lower than those with 100 larvae (55.7±1.53%) or 200 larvae (53.3±5.4%). The splenectomized young rats with 100 larvae had a significantly higher recovery rate (84.3±2.5%) than the intact (75.0±6.6%) or sham splenectomized ones (74.4±3.8%). Although titers of antibody against A. cantonensis increased with time, those against young adults were significantly higher before week 4 whereas those against adult worms become significantly higher since week 4. Titers in the splenectomized rats were also found to be significantly lower than those in the intact ones. These finding indicate that young rats are more susceptible to A. cantonensis. Crowding effect may occur in rats with heavy infections. The effects of splenectomy on the host are independent of the intensity of infection.

Therapeutic Effect and Immune Changes after Treatment of Hymenolepis nana-Infected BALB/c Mice with Compounds Isolated from Leucaena leucocephala.

BACKGROUND/PURPOSE: Hymenolepis nana is globally distributed. Leucaena leucocephala has been studied as a treatment, including the nematodes and protozoa, but no research results are related to cestodes. Therefore, the aim of this study was to target H. nana. METHODS: The natural components of L. leucocephala were isolated and added to H. nana, which was cultured in vitro, to observe changes in the mortality, motility, and morphology. BALB/c male mice infected with H. nana were treated with effective components of L. leucocephala for 10 days, and the changes were recorded. After the mice were sacrificed, the spleen weight was measured, and a primary culture was performed for the subsequent cytokine and chemokine testing. RESULTS: The experiment found that 132-hydroxy-(132-S)-pheophytin a and aristophyll-C have clear cestocidal effects in vitro. 132-hydroxy-(132-S)-pheophytin a has been shown to be effective at reducing parasite populations and eliciting host immune responses in vivo. IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, and GM-CSF in 132-hydroxy-(132-S)-pheophytin a were significantly increased after stimulation, while IL-1α, IL-1ß, IL-3, IL-12p70, and RANTES were unchanged. CONCLUSIONS: The investigation shows that components of L. leucocephala have actual cestocidal activity against H. nana.

Cestocidal activities of bioactive garlic compounds against Hymenolepis nana.

Hymenolepis nana, a parasitic tapeworm distributed worldwide, is very prevalent in countries with poor sanitary conditions. Garlic is widely used as a seasoning and medicinal plant all over the world, and its derivatives have proven anti-microbial and anti-inflammatory effects. Our study explored the cestocidal and therapeutic effects of allicin derivatives against H. nana in vitro and in vivo. Worms taken from a host were cultured in vitro, and the effects of allyl sulfide (DAS), allyl disulfide (DADS) and dimethyl sulfoxide (DMSO) treatments were observed. Male BALB/c mice were then fed eggs to produce infection, given drugs for ten days and dissected. The results of this study showed that DADS in garlic exhibited good cestocidal effects in vitro and in vivo. DADS and DATS reduced motility, induced mortality and damaged body segments of worms in vitro. In vivo, the number of worms in the low-dose and high-dose DADS groups was significantly less than the infected control group. DADS effected cytokine changes in BALB/c mice after infection. IFN-γ increased, IL-2, 4, 6 and 13 decreased, and IL-5, 10 and IL-12 p70 did not change significantly. As a medicinal plant, garlic has many active ingredients that can developed as anti-microbial or parasite-related drugs.

A school-based soil-transmitted helminths survey in the Guadalcanal Province, the Solomon Islands.

Infections by soil-transmitted helminths are a major public health problem worldwide, especially among schoolchildren in low-income countries. Little information is described about their prevalence in the Solomon Islands. From 2017 to 2018, a school-based soil-transmitted helminths survey in the Guadalcanal Province was conducted. A total of 454 schoolchildren were selected; the Merthiolate-iodine-formaldehyde concentration and stain was used. The prevalence was 17% of one or more parasites, including hookworm (8.8%), Strongyloides stercoralis (5.7%), Ascaris lumbricoides (4.2%) and Trichuris trichiura (3.5%). STH infection was significantly correlated with parents' occupations, hand washing, shoe wearing as well as gastrointestinal symptoms. To prevent STH transmission for schoolchildren in the Solomon Islands completely, combined preventive strategies seem necessary.

Larvicidal constituents of Zingiber officinale (ginger) against Anisakis simplex.

In this study, we investigated the anthelmintic activity of [10]-shogaol, [6]-shogaol, [10]-gingerol and [6]-gingerol, compounds isolated from the roots of Zingiber officinale L., Zingiberaceae (ginger), against Anisakis simplex. The above compounds kill or reduce spontaneous movement in A. simplex larvae. The maximum lethal efficacy of [10]-shogaol and [10]-gingerol was approximately 80% and 100%, respectively. We further examined the time course of compound-induced loss of mobility in A. simplex. The results showed that various concentrations of [10]-shogaol, [6]-shogaol, [10]-gingerol and [6]-gingerol have maximum effects on loss of spontaneous movement from 24 to 72 h. In addition, the time course of mortality and the percentage of loss of spontaneous movements were ascertained to determine the minimum effective doses of [10]-gingerol and [10]-shogaol. [10]-Gingerol exhibited a larger maximum larvicidal effect and greater loss of spontaneous movement than [10]-shogaol and albendazole. In addition, these constituents of Zingiber officinale showed effects against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and peroxyl radicals. These constituents of Zingiber officinale are responsible for its larvicidal activity against A. simplex.

Oxidative stress in mice infected with Angiostrongylus cantonensis coincides with enhanced glutathione-dependent enzymes activity.

This study aimed to estimate reactive oxygen species (ROS) production, antioxidants activity, and biomarkers level of oxidative damage to protein and DNA in the cerebrospinal fluid (CSF) of C57BL/6 mice infected with Angiostrongylus cantonensis. The mean ROS concentration in the CSF of infected mice increased gradually, and the increase in ROS in CSF became statistical significance at days 12-30 post-infection compared to that before infection (P<0.001), and then ROS returned to normal level at day 45 after infection. In parallel with the increase in ROS in the CSF, infected mice showed similar of changes in reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST) as that in ROS in the CSF. GSH, GR, GPx, and GST in the CSF of infected mice were all significantly higher than they were before infection during days 12-30 post-infection. However, protein carbonyl content and 8-hydroxy-2'-deoxyguanosine, biomarkers of oxidative damage to protein and DNA, respectively, were also significantly higher in the CSF of infected mice during this period. These results suggest that oxidative stress occur in the cells of central nervous system of mice infected with A. cantonensis during days 12-30 after infection due to ROS overproduction in CSF despite the increase in antioxidants during this period.

Galectin-9-like from Angiostrongylus cantonensis young adult worms modulates eosinophil chemotaxis in vitro.

BACKGROUND/PURPOSE: Eosinophils are recruited to the brain of mice after infection with Angiostrongylus canonensis. Several factors produced by infected mice are well known playing the role to chemoattract eosinophils from the blood into the brain. The purpose of this study is to investigate whether Angiostronylus cantonensis young-adult worms (AcYA) have components which have eosinophilic chemotactic activity. METHODS: Eosinophil chemotactic activity of AcYA was tested by Boyden blind-well chamber technique. The components of AcYA were analysed by SDS-PAGE and Mass spectrometry. Furthermore, galectin-9 in the cerebrospinal fluid (CSF) of infected mice and galectin-9-like in AcYA were measured by ELISA technic and also were recognized by western blot analysis respectively. RESULTS: Excretory-secretory products of AcYA did not show eosinophil chemotactic activity. However, the extracts of AcYA showed protein concentration-dependent eosinophil chemotactic activity and reached the peak at the 24 µg/ml. The eosinophil chemotactic activity was significantly reduced by lactose. The components of AcYA at molecular weights of approximatively 15 kDa and 35 kDa showed several galectins component in Mass spectrometric analysis. Furthermore, galectin-9-like in AcYA was recognized by ELISA and western blot analysis. In parallel with increase of galectin-9 in the CSF, eosinophils were also significantly increased in mouse after infected with A. cantonensis. CONCLUSION: Galectin-9-like in AcYA and galectin-9 in mouse CSF were confirmed demonstrating eosinophil chemotactic activity both in vitro study and in the infection of mouse in this study.

Increased 14-3-3ß and γ protein isoform expressions in parasitic eosinophilic meningitis caused by Angiostrongylus cantonensis infection in mice.

The 14-3-3 proteins are cerebrospinal fluid (CSF) markers of neuronal damage during infectious meningitis and Creutzfeldt-Jakob disease. Little is known about dynamic changes in the individual isoforms in response to parasitic eosinophilic meningitis. The purposes of this study were to determine the 14-3-3 protein isoform patterns, examine the kinetics and correlate the severity of blood brain barrier (BBB) damage with the expressions of these markers in mice with eosinophilic meningitis. Mice were orally infected with 50 A. cantonensis L3 via an oro-gastric tube and sacrificed every week for 3 consecutive weeks after infection. The Evans blue method and BBB junctional protein expressions were used to measure changes in the BBB. Hematoxylin and eosin staining was used to analyze pathological changes in the mice brains following 1-3 weeks of infection with A. cantonensis. The levels of 14-3-3 protein isoforms in serum/CSF and brain homogenates were analyzed by Western blot, and immunohistochemistry (IHC) was used to explore the different isoform distributions of 14-3-3 proteins and changes in BBB junctional proteins in the mice brain meninges. Dexamethasone was injected intraperitoneally from the seventh day post infection (dpi) until the end of the study (21 dpi) to study the changes in BBB junctional proteins. The amounts of Evans blue, tight junction and 14-3-3 protein isoforms in the different groups of mice were compared using the nonparametric Kruskal-Wallis test. There were significant increases in 14-3-3 protein isoforms ß and γ in the CSF in the second and third weeks after infection compared to the controls and first week of infection, which were correlated with the severity of BBB damage in brain histology, and Evans blue extravasation. Using IHC to assess the distribution of 14-3-3 protein isoforms and changes in BBB junctional proteins in the mice brain meninges, the expressions of isoforms ß, γ, ε, and θ and junctional proteins occludin and claudin-5 in the brain meninges increased over a 3-week period after infection compared to the controls and 1 week after infection. The administration of dexamethasone decreased the expressions of BBB junctional proteins occludin and claudin-5 in the mice brain meninges. Our findings support that 14-3-3 proteins ß and γ can potentially be used as a CSF marker of neuronal damage in parasitic eosinophilic meningitis caused by A. cantonensis.

Association of matrix metalloproteinase-9 and tissue inhibitors of metalloproteinase-4 in cerebrospinal fluid with blood-brain barrier dysfunction in patients with eosinophilic meningitis caused by Angiostrongylus cantonensis.

To evaluate possible blood-brain barrier (BBB) dysfunction caused by matrix metalloproteinase-9 (MMP-9) and its regulation by tissue inhibitors of metalloproteinase (TIMPs) in patients with eosinophilic meningitis caused by infection with Angiostrongylus cantonensis, 40 patients and 28 controls were included in this study. Concentrations of MMP-2, MMP-9, TIMP-1, and cerebrospinal fluid (CSF):serum albumin ratios (Q(Alb) values) were significantly increased in patients compared with controls. However, concentrations of TIMP-4 were significantly lower in patients. In contrast to MMP-2, proteolytic activity of MMP-9 detected by gelatin zymography was only observed in patients with eosinophilic meningitis. We detected higher levels of antibodies specific for A. cantonensis and higher Q(Alb) values and MMP-9 concentrations in CSF of patients with eosinophilic meningitis, Furthermore, the increase in the Q(Alb) value was significantly correlated with the increase in MMP-9 in patients. In parallel with CSF MMP-9, patients also showed an increase in CSF leukocyte counts. Gradual decreases in levels of Q(Alb), MMP-9, and TIMP-1 and increases in levels of TIMP-4 were observed in six patients during recovery from eosinophilic meningitis. These results suggest that the source of MMP-9 in CSF of patients with eosinophilic meningitis was probably associated with leukocytes migrating from peripheral blood to CSF. Activity of MMP-9 in CSF of patients could not be completely inhibited because of the decrease of TIMP-4, which may cause BBB dysfunction, as shown by higher Q(Alb) values in patients.

Anticancer activity of isoobtusilactone A from Cinnamomum kotoense: involvement of apoptosis, cell-cycle dysregulation, mitochondria regulation, and reactive oxygen species.

In this study, we investigate the anticancer effect of isoobtusilactone A (IOA), a constituent isolated from the leaves of Cinnamomum kotoense, on human non-small cell lung cancer (NSCLC) A549 cells. IOA was found to induce the arrest of G2-M phase, induce apoptosis, increase sub-G1, and inhibit the growth of these cells. Further investigation revealed that IOA's blockade of the cell cycle was associated with increased levels of p21/WAF1, p27 (kip1), and p53. In addition, IOA triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratios, resulting in a loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of PARP. We also found the generation of reactive oxygen species (ROS) to be a critical mediator in IOA-induced inhibition of A549 cell growth. In antioxidant and NO inhibitor studies, we found that by pretreating A549 cells with either N-acetylcystenine (NAC), catalase, mannitol, dexamethasone, trolox, or L-NAME we could significantly decrease IOA production of ROS. Moreover, using NAC to block ROS, we could significantly suppress IOA-induced antiproliferation, antimigration, and anti-invasion. Finally, we found that IOA inhibited the migration and invasion of A549 cell migration and invasion. Taken together, these results suggest that IOA has anticancer effects on A549 cells.

Dynamic changes of matrix metalloproteinase-9 in patients with Klebsiella pneumoniae meningitis.

To quantitate cerebrospinal fluid (CSF) concentrations of matrix metalloproteinase 9 (MMP-9) in adult patients with Klebsiella pneumoniae meningitis and to correlate levels of MMP-9 with parameters of intrathecal inflammation and analyze the kinetic changes of MMP-9. In a prospective cohort study, levels of MMP-9 and tissue inhibitor of matrix metalloproteinase (TIMP-1) concentrations were measured in the CSF of six adult patients with meningitis and 11 controls. MMP-9 and TIMP-1 were detected in all of the six patients at presentation and follow up lumbar puncture. CSF levels of MMP-9 (6.71+/-7.29 ng/ml) and TIMP-1(454.3+/-242.9 ng/ml) were higher in patients than in the control group (0.07+/-0.11 ng/ml and 27.14+/-39.34 ng/ml, respectively). Levels of MMP-9 correlated with CSF concentrations of protein, cell count and lactate. Repeated lumbar punctures showed that levels of MMP-9 decrease during clinical recovery, although the levels of MMP-9 in the CSF are variable because of the small number of cases. The relative change in gelatin zymography is comparable to the changes of MMP-9 levels found in ELISA. MMP-9 levels in CSF may be a useful tool in follow-up in patients with K. pneumoniae meningitis.

Enterobius vermicularis infection and its risk factors among pre-school children in Taipei, Taiwan.

BACKGROUND: The prevalence of pinworm infection is extremely low in Taipei, Taiwan. This population study was designed to determine the current status and the associated risk factors of this infection among pre-school children. METHODS: Perianal swab specimens were obtained from the parents or guardians using a two-consecutive-day adhesive cellophane perianal swab kit. Information of family background, personal hygiene, and household sanitary conditions were collected by asking the parents or guardians to complete a questionnaire. RESULTS: Of 44,163 children, 0.21% was found to infect with pinworm. The positive rate was highest in Datong (0.59%) and Nangang (0.58%) Districts and lowest in Neihu District (0.02%). There was no significant difference in the rates by gender (boys 0.24% and girls 0.19%) or school (kindergartens 0.25% and nurseries 0.17%). Significantly higher positive rates were found in children having parent with lower educational level and elder brother(s)/sister(s). Children taking bath by themselves and those sleeping in bed with matting had significantly higher positive rates. Five significant independent predictors of pinworm infection were determined by multivariate analysis: having elder brother(s), having elder sister(s), infrequent washing hands after using toilet facilities, bathing without the help of family members, and sleeping on bed with matting. CONCLUSION: The prevalence of pinworm infection in the pre-school children of Taipei is extremely low and decreasing. Good hand washing habit should be an important preventive measure. Transmission of this infection in pre-school children may occur in the family through their school-age siblings.

Eosinophilic meningitis caused by Angiostrongylus cantonensis after ingestion of raw frogs.

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis in humans after ingestion of raw or inadequately cooked intermediate hosts or food contaminated with infective third-stage larvae. Frogs are known to be a paratenic host of A. cantonensis, but have never been reported as the infectious source of human angiostrongyliasis in Taiwan. We report the first case of eosinophilic meningitis caused by A. cantonensis after ingestion of raw frogs (Rana plancyi).

Vascular endothelial growth factor is associated with blood brain barrier dysfunction in eosinophilic meningitis caused by Angiostrongylus cantonensis infection.

Vascular endothelial growth factor (VEGF) is a potent vascular permeability factor and a mediator of brain edema. To assess the role of vascular endothelial growth factor in eosinophilic meningitis, vascular endothelial growth factor was measured in the cerebrospinal fluid (CSF) and blood of 9 patients with eosinophilic meningitis in a cohort study. VEGFCSF was detected in 8 (90%) of 9 eosinophilic meningitis patients (range, 45-2190 pg/mL) at presentation. The mean VEGFCSF at presentation, 1 week, and 2 weeks after admission was 568 pg/mL, 751 pg/mL, and 1031 pg/mL, respectively. There was an association between VEGFCSF, CSF protein, white cell count, and eosinophil counts. The VEGFSERUM fluctuated during the 6-month follow-up period. These results indicate that vascular endothelial growth factor may be associated with blood-brain barrier disruption in patients with eosinophilic meningitis.

Excretory/secretory proteases and mechanical movement of Anisakis pegreffii infective larvae in the penetration of BALB/c mice gastrointestine.

Anisakiasis is a human parasitic disease caused by infection with the infective larvae of Anisakis. Accidental infection in humans causes the gastrointestinal pathophysiological effects of mechanical tissue damage by migrating larvae. The mechanism of the infective larval invasion and migration is suspected to involve larval excretory/secretory proteases and motility. This study demonstrates the penetration rate of the infective larvae of Anisakis pegreffii in mouse gastrointestine depends on the time after infection, and that only 15% of larvae remain in the gastrointestinal tract 3 h after infection. Strong activities of matrix metalloproteinases (MMPs) and serine proteases, especially plasmin, were found in the excretory/secretory products of A. pegreffii; these can be inhibited by ONO-4817 and phenylmethylsulfonyl fluoride, respectively. The protease activity was also significantly decreased in another 1 h of cultivation of larvae in fresh 0.9% normal saline (NS) after previous cultivation for 48 h in NS. The motility scores of larvae were significantly lower after 48 h of cultivation in NS. The penetration rate of A. pegreffii larvae in the gastrointestine of infected mice sequentially were 90% in the freshly prepared, 68% in serine protease inhibited, 55% in MMPs inhibited larvae, and 16% in larvae cultivated in NS for 48 h. Therefore, this study demonstrates that MMPs and serine proteases excreted and secreted by A. pegreffii and the mechanical movement of infective larvae participate in the penetration of the gastrointestine of mice after infection.

Blood-brain barrier dysfunction occurring in mice infected with Angiostrongylus cantonensis.

Several indices were used to assess whether blood-brain barrier (BBB) damage occurs in neurological disorders. Dysfunction of the BBB was surmised to be involved in the pathological changes of eosinophilic meningitis caused by the infection of Angiostrongylus cantonensis. The mean concentration of protein and albumin in the cerebrospinal fluid (CSF) of infected mice gradually increased from days 0 to 18 after infection and then rapidly increased 21 days after infection. The concentrations of protein and albumin in the CSF of infected mice 15 days after infection were all significantly higher than those in uninfected mice (all P-values at least <0.05). Parallel with the increase in protein and albumin in the CSF, infected mice showed a gradual increase in their CSF/serum protein and albumin ratios. The increase became significant at days 21 and 18 after infection, respectively (P<0.01 and P<0.05, respectively). The higher the worm counts in the brain, the higher the CSF/serum albumin ratio was observed in infected mice at day 21 after infection (P<0.001). In addition, the ratios of the CSF/serum albumin were positively correlated with the worm counts in the brain (P<0.001). The total leukocyte and eosinophil counts were also positively correlated with ratios of CSF/serum albumin (P<0.01). The amount of Evans blue in the brain of mice 21 days after infection from peripheral blood via BBB became significantly increased than those in uninfected mice (P<0.001). Thus, the evidence of high concentrations of protein and albumin, high leukocyte counts in CSF, high ratio of CSF/serum protein and albumin, and high permeability of BBB show that dysfunction of the BBB occurred in mice infected with A. cantonensis.